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Diffstat (limited to 'can-config-generator/3rdparty/json/json.hpp')
| -rwxr-xr-x | can-config-generator/3rdparty/json/json.hpp | 13003 |
1 files changed, 0 insertions, 13003 deletions
diff --git a/can-config-generator/3rdparty/json/json.hpp b/can-config-generator/3rdparty/json/json.hpp deleted file mode 100755 index 6dfc1831..00000000 --- a/can-config-generator/3rdparty/json/json.hpp +++ /dev/null @@ -1,13003 +0,0 @@ -/* - __ _____ _____ _____ - __| | __| | | | JSON for Modern C++ -| | |__ | | | | | | version 2.1.1 -|_____|_____|_____|_|___| https://github.com/nlohmann/json - -Licensed under the MIT License <http://opensource.org/licenses/MIT>. -Copyright (c) 2013-2017 Niels Lohmann <http://nlohmann.me>. - -Permission is hereby granted, free of charge, to any person obtaining a copy -of this software and associated documentation files (the "Software"), to deal -in the Software without restriction, including without limitation the rights -to use, copy, modify, merge, publish, distribute, sublicense, and/or sell -copies of the Software, and to permit persons to whom the Software is -furnished to do so, subject to the following conditions: - -The above copyright notice and this permission notice shall be included in all -copies or substantial portions of the Software. - -THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR -IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, -FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE -AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER -LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, -OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE -SOFTWARE. -*/ - -#ifndef NLOHMANN_JSON_HPP -#define NLOHMANN_JSON_HPP - -#include <algorithm> // all_of, copy, fill, find, for_each, none_of, remove, reverse, transform -#include <array> // array -#include <cassert> // assert -#include <cctype> // isdigit -#include <ciso646> // and, not, or -#include <cmath> // isfinite, labs, ldexp, signbit -#include <cstddef> // nullptr_t, ptrdiff_t, size_t -#include <cstdint> // int64_t, uint64_t -#include <cstdlib> // abort, strtod, strtof, strtold, strtoul, strtoll, strtoull -#include <cstring> // strlen -#include <forward_list> // forward_list -#include <functional> // function, hash, less -#include <initializer_list> // initializer_list -#include <iomanip> // setw -#include <iostream> // istream, ostream -#include <iterator> // advance, begin, back_inserter, bidirectional_iterator_tag, distance, end, inserter, iterator, iterator_traits, next, random_access_iterator_tag, reverse_iterator -#include <limits> // numeric_limits -#include <locale> // locale -#include <map> // map -#include <memory> // addressof, allocator, allocator_traits, unique_ptr -#include <numeric> // accumulate -#include <sstream> // stringstream -#include <stdexcept> // domain_error, invalid_argument, out_of_range -#include <string> // getline, stoi, string, to_string -#include <type_traits> // add_pointer, conditional, decay, enable_if, false_type, integral_constant, is_arithmetic, is_base_of, is_const, is_constructible, is_convertible, is_default_constructible, is_enum, is_floating_point, is_integral, is_nothrow_move_assignable, is_nothrow_move_constructible, is_pointer, is_reference, is_same, is_scalar, is_signed, remove_const, remove_cv, remove_pointer, remove_reference, true_type, underlying_type -#include <utility> // declval, forward, make_pair, move, pair, swap -#include <vector> // vector - -// exclude unsupported compilers -#if defined(__clang__) - #if (__clang_major__ * 10000 + __clang_minor__ * 100 + __clang_patchlevel__) < 30400 - #error "unsupported Clang version - see https://github.com/nlohmann/json#supported-compilers" - #endif -#elif defined(__GNUC__) - #if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40900 - #error "unsupported GCC version - see https://github.com/nlohmann/json#supported-compilers" - #endif -#endif - -// disable float-equal warnings on GCC/clang -#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) - #pragma GCC diagnostic push - #pragma GCC diagnostic ignored "-Wfloat-equal" -#endif - -// disable documentation warnings on clang -#if defined(__clang__) - #pragma GCC diagnostic push - #pragma GCC diagnostic ignored "-Wdocumentation" -#endif - -// allow for portable deprecation warnings -#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) - #define JSON_DEPRECATED __attribute__((deprecated)) -#elif defined(_MSC_VER) - #define JSON_DEPRECATED __declspec(deprecated) -#else - #define JSON_DEPRECATED -#endif - -// allow to disable exceptions -#if not defined(JSON_NOEXCEPTION) || defined(__EXCEPTIONS) - #define JSON_THROW(exception) throw exception - #define JSON_TRY try - #define JSON_CATCH(exception) catch(exception) -#else - #define JSON_THROW(exception) std::abort() - #define JSON_TRY if(true) - #define JSON_CATCH(exception) if(false) -#endif - -/*! -@brief namespace for Niels Lohmann -@see https://github.com/nlohmann -@since version 1.0.0 -*/ -namespace nlohmann -{ - -/*! -@brief unnamed namespace with internal helper functions - -This namespace collects some functions that could not be defined inside the -@ref basic_json class. - -@since version 2.1.0 -*/ -namespace detail -{ -/////////////////////////// -// JSON type enumeration // -/////////////////////////// - -/*! -@brief the JSON type enumeration - -This enumeration collects the different JSON types. It is internally used to -distinguish the stored values, and the functions @ref basic_json::is_null(), -@ref basic_json::is_object(), @ref basic_json::is_array(), -@ref basic_json::is_string(), @ref basic_json::is_boolean(), -@ref basic_json::is_number() (with @ref basic_json::is_number_integer(), -@ref basic_json::is_number_unsigned(), and @ref basic_json::is_number_float()), -@ref basic_json::is_discarded(), @ref basic_json::is_primitive(), and -@ref basic_json::is_structured() rely on it. - -@note There are three enumeration entries (number_integer, number_unsigned, and -number_float), because the library distinguishes these three types for numbers: -@ref basic_json::number_unsigned_t is used for unsigned integers, -@ref basic_json::number_integer_t is used for signed integers, and -@ref basic_json::number_float_t is used for floating-point numbers or to -approximate integers which do not fit in the limits of their respective type. - -@sa @ref basic_json::basic_json(const value_t value_type) -- create a JSON -value with the default value for a given type - -@since version 1.0.0 -*/ -enum class value_t : uint8_t -{ - null, ///< null value - object, ///< object (unordered set of name/value pairs) - array, ///< array (ordered collection of values) - string, ///< string value - boolean, ///< boolean value - number_integer, ///< number value (signed integer) - number_unsigned, ///< number value (unsigned integer) - number_float, ///< number value (floating-point) - discarded ///< discarded by the the parser callback function -}; - -/*! -@brief comparison operator for JSON types - -Returns an ordering that is similar to Python: -- order: null < boolean < number < object < array < string -- furthermore, each type is not smaller than itself - -@since version 1.0.0 -*/ -inline bool operator<(const value_t lhs, const value_t rhs) noexcept -{ - static constexpr std::array<uint8_t, 8> order = {{ - 0, // null - 3, // object - 4, // array - 5, // string - 1, // boolean - 2, // integer - 2, // unsigned - 2, // float - } - }; - - // discarded values are not comparable - if (lhs == value_t::discarded or rhs == value_t::discarded) - { - return false; - } - - return order[static_cast<std::size_t>(lhs)] < - order[static_cast<std::size_t>(rhs)]; -} - - -///////////// -// helpers // -///////////// - -// alias templates to reduce boilerplate -template<bool B, typename T = void> -using enable_if_t = typename std::enable_if<B, T>::type; - -template<typename T> -using uncvref_t = typename std::remove_cv<typename std::remove_reference<T>::type>::type; - -// taken from http://stackoverflow.com/a/26936864/266378 -template<typename T> -using is_unscoped_enum = - std::integral_constant<bool, std::is_convertible<T, int>::value and - std::is_enum<T>::value>; - -/* -Implementation of two C++17 constructs: conjunction, negation. This is needed -to avoid evaluating all the traits in a condition - -For example: not std::is_same<void, T>::value and has_value_type<T>::value -will not compile when T = void (on MSVC at least). Whereas -conjunction<negation<std::is_same<void, T>>, has_value_type<T>>::value will -stop evaluating if negation<...>::value == false - -Please note that those constructs must be used with caution, since symbols can -become very long quickly (which can slow down compilation and cause MSVC -internal compiler errors). Only use it when you have to (see example ahead). -*/ -template<class...> struct conjunction : std::true_type {}; -template<class B1> struct conjunction<B1> : B1 {}; -template<class B1, class... Bn> -struct conjunction<B1, Bn...> : std::conditional<bool(B1::value), conjunction<Bn...>, B1>::type {}; - -template<class B> struct negation : std::integral_constant < bool, !B::value > {}; - -// dispatch utility (taken from ranges-v3) -template<unsigned N> struct priority_tag : priority_tag < N - 1 > {}; -template<> struct priority_tag<0> {}; - - -////////////////// -// constructors // -////////////////// - -template<value_t> struct external_constructor; - -template<> -struct external_constructor<value_t::boolean> -{ - template<typename BasicJsonType> - static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept - { - j.m_type = value_t::boolean; - j.m_value = b; - j.assert_invariant(); - } -}; - -template<> -struct external_constructor<value_t::string> -{ - template<typename BasicJsonType> - static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s) - { - j.m_type = value_t::string; - j.m_value = s; - j.assert_invariant(); - } -}; - -template<> -struct external_constructor<value_t::number_float> -{ - template<typename BasicJsonType> - static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept - { - // replace infinity and NAN by null - if (not std::isfinite(val)) - { - j = BasicJsonType{}; - } - else - { - j.m_type = value_t::number_float; - j.m_value = val; - } - j.assert_invariant(); - } -}; - -template<> -struct external_constructor<value_t::number_unsigned> -{ - template<typename BasicJsonType> - static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept - { - j.m_type = value_t::number_unsigned; - j.m_value = val; - j.assert_invariant(); - } -}; - -template<> -struct external_constructor<value_t::number_integer> -{ - template<typename BasicJsonType> - static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept - { - j.m_type = value_t::number_integer; - j.m_value = val; - j.assert_invariant(); - } -}; - -template<> -struct external_constructor<value_t::array> -{ - template<typename BasicJsonType> - static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr) - { - j.m_type = value_t::array; - j.m_value = arr; - j.assert_invariant(); - } - - template<typename BasicJsonType, typename CompatibleArrayType, - enable_if_t<not std::is_same<CompatibleArrayType, - typename BasicJsonType::array_t>::value, - int> = 0> - static void construct(BasicJsonType& j, const CompatibleArrayType& arr) - { - using std::begin; - using std::end; - j.m_type = value_t::array; - j.m_value.array = j.template create<typename BasicJsonType::array_t>(begin(arr), end(arr)); - j.assert_invariant(); - } -}; - -template<> -struct external_constructor<value_t::object> -{ - template<typename BasicJsonType> - static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj) - { - j.m_type = value_t::object; - j.m_value = obj; - j.assert_invariant(); - } - - template<typename BasicJsonType, typename CompatibleObjectType, - enable_if_t<not std::is_same<CompatibleObjectType, - typename BasicJsonType::object_t>::value, - int> = 0> - static void construct(BasicJsonType& j, const CompatibleObjectType& obj) - { - using std::begin; - using std::end; - - j.m_type = value_t::object; - j.m_value.object = j.template create<typename BasicJsonType::object_t>(begin(obj), end(obj)); - j.assert_invariant(); - } -}; - - -//////////////////////// -// has_/is_ functions // -//////////////////////// - -/*! -@brief Helper to determine whether there's a key_type for T. - -This helper is used to tell associative containers apart from other containers -such as sequence containers. For instance, `std::map` passes the test as it -contains a `mapped_type`, whereas `std::vector` fails the test. - -@sa http://stackoverflow.com/a/7728728/266378 -@since version 1.0.0, overworked in version 2.0.6 -*/ -#define NLOHMANN_JSON_HAS_HELPER(type) \ - template<typename T> struct has_##type { \ - private: \ - template<typename U, typename = typename U::type> \ - static int detect(U &&); \ - static void detect(...); \ - public: \ - static constexpr bool value = \ - std::is_integral<decltype(detect(std::declval<T>()))>::value; \ - } - -NLOHMANN_JSON_HAS_HELPER(mapped_type); -NLOHMANN_JSON_HAS_HELPER(key_type); -NLOHMANN_JSON_HAS_HELPER(value_type); -NLOHMANN_JSON_HAS_HELPER(iterator); - -#undef NLOHMANN_JSON_HAS_HELPER - - -template<bool B, class RealType, class CompatibleObjectType> -struct is_compatible_object_type_impl : std::false_type {}; - -template<class RealType, class CompatibleObjectType> -struct is_compatible_object_type_impl<true, RealType, CompatibleObjectType> -{ - static constexpr auto value = - std::is_constructible<typename RealType::key_type, - typename CompatibleObjectType::key_type>::value and - std::is_constructible<typename RealType::mapped_type, - typename CompatibleObjectType::mapped_type>::value; -}; - -template<class BasicJsonType, class CompatibleObjectType> -struct is_compatible_object_type -{ - static auto constexpr value = is_compatible_object_type_impl < - conjunction<negation<std::is_same<void, CompatibleObjectType>>, - has_mapped_type<CompatibleObjectType>, - has_key_type<CompatibleObjectType>>::value, - typename BasicJsonType::object_t, CompatibleObjectType >::value; -}; - -template<typename BasicJsonType, typename T> -struct is_basic_json_nested_type -{ - static auto constexpr value = std::is_same<T, typename BasicJsonType::iterator>::value or - std::is_same<T, typename BasicJsonType::const_iterator>::value or - std::is_same<T, typename BasicJsonType::reverse_iterator>::value or - std::is_same<T, typename BasicJsonType::const_reverse_iterator>::value or - std::is_same<T, typename BasicJsonType::json_pointer>::value; -}; - -template<class BasicJsonType, class CompatibleArrayType> -struct is_compatible_array_type -{ - static auto constexpr value = - conjunction<negation<std::is_same<void, CompatibleArrayType>>, - negation<is_compatible_object_type< - BasicJsonType, CompatibleArrayType>>, - negation<std::is_constructible<typename BasicJsonType::string_t, - CompatibleArrayType>>, - negation<is_basic_json_nested_type<BasicJsonType, CompatibleArrayType>>, - has_value_type<CompatibleArrayType>, - has_iterator<CompatibleArrayType>>::value; -}; - -template<bool, typename, typename> -struct is_compatible_integer_type_impl : std::false_type {}; - -template<typename RealIntegerType, typename CompatibleNumberIntegerType> -struct is_compatible_integer_type_impl<true, RealIntegerType, CompatibleNumberIntegerType> -{ - // is there an assert somewhere on overflows? - using RealLimits = std::numeric_limits<RealIntegerType>; - using CompatibleLimits = std::numeric_limits<CompatibleNumberIntegerType>; - - static constexpr auto value = - std::is_constructible<RealIntegerType, - CompatibleNumberIntegerType>::value and - CompatibleLimits::is_integer and - RealLimits::is_signed == CompatibleLimits::is_signed; -}; - -template<typename RealIntegerType, typename CompatibleNumberIntegerType> -struct is_compatible_integer_type -{ - static constexpr auto value = - is_compatible_integer_type_impl < - std::is_integral<CompatibleNumberIntegerType>::value and - not std::is_same<bool, CompatibleNumberIntegerType>::value, - RealIntegerType, CompatibleNumberIntegerType > ::value; -}; - - -// trait checking if JSONSerializer<T>::from_json(json const&, udt&) exists -template<typename BasicJsonType, typename T> -struct has_from_json -{ - private: - // also check the return type of from_json - template<typename U, typename = enable_if_t<std::is_same<void, decltype(uncvref_t<U>::from_json( - std::declval<BasicJsonType>(), std::declval<T&>()))>::value>> - static int detect(U&&); - static void detect(...); - - public: - static constexpr bool value = std::is_integral<decltype( - detect(std::declval<typename BasicJsonType::template json_serializer<T, void>>()))>::value; -}; - -// This trait checks if JSONSerializer<T>::from_json(json const&) exists -// this overload is used for non-default-constructible user-defined-types -template<typename BasicJsonType, typename T> -struct has_non_default_from_json -{ - private: - template < - typename U, - typename = enable_if_t<std::is_same< - T, decltype(uncvref_t<U>::from_json(std::declval<BasicJsonType>()))>::value >> - static int detect(U&&); - static void detect(...); - - public: - static constexpr bool value = std::is_integral<decltype(detect( - std::declval<typename BasicJsonType::template json_serializer<T, void>>()))>::value; -}; - -// This trait checks if BasicJsonType::json_serializer<T>::to_json exists -template<typename BasicJsonType, typename T> -struct has_to_json -{ - private: - template<typename U, typename = decltype(uncvref_t<U>::to_json( - std::declval<BasicJsonType&>(), std::declval<T>()))> - static int detect(U&&); - static void detect(...); - - public: - static constexpr bool value = std::is_integral<decltype(detect( - std::declval<typename BasicJsonType::template json_serializer<T, void>>()))>::value; -}; - - -///////////// -// to_json // -///////////// - -template<typename BasicJsonType, typename T, enable_if_t< - std::is_same<T, typename BasicJsonType::boolean_t>::value, int> = 0> -void to_json(BasicJsonType& j, T b) noexcept -{ - external_constructor<value_t::boolean>::construct(j, b); -} - -template<typename BasicJsonType, typename CompatibleString, - enable_if_t<std::is_constructible<typename BasicJsonType::string_t, - CompatibleString>::value, int> = 0> -void to_json(BasicJsonType& j, const CompatibleString& s) -{ - external_constructor<value_t::string>::construct(j, s); -} - -template<typename BasicJsonType, typename FloatType, - enable_if_t<std::is_floating_point<FloatType>::value, int> = 0> -void to_json(BasicJsonType& j, FloatType val) noexcept -{ - external_constructor<value_t::number_float>::construct(j, static_cast<typename BasicJsonType::number_float_t>(val)); -} - -template < - typename BasicJsonType, typename CompatibleNumberUnsignedType, - enable_if_t<is_compatible_integer_type<typename BasicJsonType::number_unsigned_t, - CompatibleNumberUnsignedType>::value, int> = 0 > -void to_json(BasicJsonType& j, CompatibleNumberUnsignedType val) noexcept -{ - external_constructor<value_t::number_unsigned>::construct(j, static_cast<typename BasicJsonType::number_unsigned_t>(val)); -} - -template < - typename BasicJsonType, typename CompatibleNumberIntegerType, - enable_if_t<is_compatible_integer_type<typename BasicJsonType::number_integer_t, - CompatibleNumberIntegerType>::value, int> = 0 > -void to_json(BasicJsonType& j, CompatibleNumberIntegerType val) noexcept -{ - external_constructor<value_t::number_integer>::construct(j, static_cast<typename BasicJsonType::number_integer_t>(val)); -} - -template<typename BasicJsonType, typename UnscopedEnumType, - enable_if_t<is_unscoped_enum<UnscopedEnumType>::value, int> = 0> -void to_json(BasicJsonType& j, UnscopedEnumType e) noexcept -{ - external_constructor<value_t::number_integer>::construct(j, e); -} - -template < - typename BasicJsonType, typename CompatibleArrayType, - enable_if_t < - is_compatible_array_type<BasicJsonType, CompatibleArrayType>::value or - std::is_same<typename BasicJsonType::array_t, CompatibleArrayType>::value, - int > = 0 > -void to_json(BasicJsonType& j, const CompatibleArrayType& arr) -{ - external_constructor<value_t::array>::construct(j, arr); -} - -template < - typename BasicJsonType, typename CompatibleObjectType, - enable_if_t<is_compatible_object_type<BasicJsonType, CompatibleObjectType>::value, - int> = 0 > -void to_json(BasicJsonType& j, const CompatibleObjectType& arr) -{ - external_constructor<value_t::object>::construct(j, arr); -} - - -/////////////// -// from_json // -/////////////// - -// overloads for basic_json template parameters -template<typename BasicJsonType, typename ArithmeticType, - enable_if_t<std::is_arithmetic<ArithmeticType>::value and - not std::is_same<ArithmeticType, - typename BasicJsonType::boolean_t>::value, - int> = 0> -void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val) -{ - switch (static_cast<value_t>(j)) - { - case value_t::number_unsigned: - { - val = static_cast<ArithmeticType>( - *j.template get_ptr<const typename BasicJsonType::number_unsigned_t*>()); - break; - } - case value_t::number_integer: - { - val = static_cast<ArithmeticType>( - *j.template get_ptr<const typename BasicJsonType::number_integer_t*>()); - break; - } - case value_t::number_float: - { - val = static_cast<ArithmeticType>( - *j.template get_ptr<const typename BasicJsonType::number_float_t*>()); - break; - } - default: - { - JSON_THROW( - std::domain_error("type must be number, but is " + j.type_name())); - } - } -} - -template<typename BasicJsonType> -void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b) -{ - if (not j.is_boolean()) - { - JSON_THROW(std::domain_error("type must be boolean, but is " + j.type_name())); - } - b = *j.template get_ptr<const typename BasicJsonType::boolean_t*>(); -} - -template<typename BasicJsonType> -void from_json(const BasicJsonType& j, typename BasicJsonType::string_t& s) -{ - if (not j.is_string()) - { - JSON_THROW(std::domain_error("type must be string, but is " + j.type_name())); - } - s = *j.template get_ptr<const typename BasicJsonType::string_t*>(); -} - -template<typename BasicJsonType> -void from_json(const BasicJsonType& j, typename BasicJsonType::number_float_t& val) -{ - get_arithmetic_value(j, val); -} - -template<typename BasicJsonType> -void from_json(const BasicJsonType& j, typename BasicJsonType::number_unsigned_t& val) -{ - get_arithmetic_value(j, val); -} - -template<typename BasicJsonType> -void from_json(const BasicJsonType& j, typename BasicJsonType::number_integer_t& val) -{ - get_arithmetic_value(j, val); -} - -template<typename BasicJsonType, typename UnscopedEnumType, - enable_if_t<is_unscoped_enum<UnscopedEnumType>::value, int> = 0> -void from_json(const BasicJsonType& j, UnscopedEnumType& e) -{ - typename std::underlying_type<UnscopedEnumType>::type val; - get_arithmetic_value(j, val); - e = static_cast<UnscopedEnumType>(val); -} - -template<typename BasicJsonType> -void from_json(const BasicJsonType& j, typename BasicJsonType::array_t& arr) -{ - if (not j.is_array()) - { - JSON_THROW(std::domain_error("type must be array, but is " + j.type_name())); - } - arr = *j.template get_ptr<const typename BasicJsonType::array_t*>(); -} - -// forward_list doesn't have an insert method -template<typename BasicJsonType, typename T, typename Allocator> -void from_json(const BasicJsonType& j, std::forward_list<T, Allocator>& l) -{ - // do not perform the check when user wants to retrieve jsons - // (except when it's null.. ?) - if (j.is_null()) - { - JSON_THROW(std::domain_error("type must be array, but is " + j.type_name())); - } - if (not std::is_same<T, BasicJsonType>::value) - { - if (not j.is_array()) - { - JSON_THROW(std::domain_error("type must be array, but is " + j.type_name())); - } - } - for (auto it = j.rbegin(), end = j.rend(); it != end; ++it) - { - l.push_front(it->template get<T>()); - } -} - -template<typename BasicJsonType, typename CompatibleArrayType> -void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<0>) -{ - using std::begin; - using std::end; - - std::transform(j.begin(), j.end(), - std::inserter(arr, end(arr)), [](const BasicJsonType & i) - { - // get<BasicJsonType>() returns *this, this won't call a from_json - // method when value_type is BasicJsonType - return i.template get<typename CompatibleArrayType::value_type>(); - }); -} - -template<typename BasicJsonType, typename CompatibleArrayType> -auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<1>) --> decltype( - arr.reserve(std::declval<typename CompatibleArrayType::size_type>()), - void()) -{ - using std::begin; - using std::end; - - arr.reserve(j.size()); - std::transform( - j.begin(), j.end(), std::inserter(arr, end(arr)), [](const BasicJsonType & i) - { - // get<BasicJsonType>() returns *this, this won't call a from_json - // method when value_type is BasicJsonType - return i.template get<typename CompatibleArrayType::value_type>(); - }); -} - -template<typename BasicJsonType, typename CompatibleArrayType, - enable_if_t<is_compatible_array_type<BasicJsonType, CompatibleArrayType>::value and - not std::is_same<typename BasicJsonType::array_t, CompatibleArrayType>::value, int> = 0> -void from_json(const BasicJsonType& j, CompatibleArrayType& arr) -{ - if (j.is_null()) - { - JSON_THROW(std::domain_error("type must be array, but is " + j.type_name())); - } - - // when T == BasicJsonType, do not check if value_t is correct - if (not std::is_same<typename CompatibleArrayType::value_type, BasicJsonType>::value) - { - if (not j.is_array()) - { - JSON_THROW(std::domain_error("type must be array, but is " + j.type_name())); - } - } - from_json_array_impl(j, arr, priority_tag<1> {}); -} - -template<typename BasicJsonType, typename CompatibleObjectType, - enable_if_t<is_compatible_object_type<BasicJsonType, CompatibleObjectType>::value, int> = 0> -void from_json(const BasicJsonType& j, CompatibleObjectType& obj) -{ - if (not j.is_object()) - { - JSON_THROW(std::domain_error("type must be object, but is " + j.type_name())); - } - - auto inner_object = j.template get_ptr<const typename BasicJsonType::object_t*>(); - using std::begin; - using std::end; - // we could avoid the assignment, but this might require a for loop, which - // might be less efficient than the container constructor for some - // containers (would it?) - obj = CompatibleObjectType(begin(*inner_object), end(*inner_object)); -} - -// overload for arithmetic types, not chosen for basic_json template arguments -// (BooleanType, etc..); note: Is it really necessary to provide explicit -// overloads for boolean_t etc. in case of a custom BooleanType which is not -// an arithmetic type? -template<typename BasicJsonType, typename ArithmeticType, - enable_if_t < - std::is_arithmetic<ArithmeticType>::value and - not std::is_same<ArithmeticType, typename BasicJsonType::number_unsigned_t>::value and - not std::is_same<ArithmeticType, typename BasicJsonType::number_integer_t>::value and - not std::is_same<ArithmeticType, typename BasicJsonType::number_float_t>::value and - not std::is_same<ArithmeticType, typename BasicJsonType::boolean_t>::value, - int> = 0> -void from_json(const BasicJsonType& j, ArithmeticType& val) -{ - switch (static_cast<value_t>(j)) - { - case value_t::number_unsigned: - { - val = static_cast<ArithmeticType>(*j.template get_ptr<const typename BasicJsonType::number_unsigned_t*>()); - break; - } - case value_t::number_integer: - { - val = static_cast<ArithmeticType>(*j.template get_ptr<const typename BasicJsonType::number_integer_t*>()); - break; - } - case value_t::number_float: - { - val = static_cast<ArithmeticType>(*j.template get_ptr<const typename BasicJsonType::number_float_t*>()); - break; - } - case value_t::boolean: - { - val = static_cast<ArithmeticType>(*j.template get_ptr<const typename BasicJsonType::boolean_t*>()); - break; - } - default: - { - JSON_THROW(std::domain_error("type must be number, but is " + j.type_name())); - } - } -} - -struct to_json_fn -{ - private: - template<typename BasicJsonType, typename T> - auto call(BasicJsonType& j, T&& val, priority_tag<1>) const noexcept(noexcept(to_json(j, std::forward<T>(val)))) - -> decltype(to_json(j, std::forward<T>(val)), void()) - { - return to_json(j, std::forward<T>(val)); - } - - template<typename BasicJsonType, typename T> - void call(BasicJsonType&, T&&, priority_tag<0>) const noexcept - { - static_assert(sizeof(BasicJsonType) == 0, - "could not find to_json() method in T's namespace"); - } - - public: - template<typename BasicJsonType, typename T> - void operator()(BasicJsonType& j, T&& val) const - noexcept(noexcept(std::declval<to_json_fn>().call(j, std::forward<T>(val), priority_tag<1> {}))) - { - return call(j, std::forward<T>(val), priority_tag<1> {}); - } -}; - -struct from_json_fn -{ - private: - template<typename BasicJsonType, typename T> - auto call(const BasicJsonType& j, T& val, priority_tag<1>) const - noexcept(noexcept(from_json(j, val))) - -> decltype(from_json(j, val), void()) - { - return from_json(j, val); - } - - template<typename BasicJsonType, typename T> - void call(const BasicJsonType&, T&, priority_tag<0>) const noexcept - { - static_assert(sizeof(BasicJsonType) == 0, - "could not find from_json() method in T's namespace"); - } - - public: - template<typename BasicJsonType, typename T> - void operator()(const BasicJsonType& j, T& val) const - noexcept(noexcept(std::declval<from_json_fn>().call(j, val, priority_tag<1> {}))) - { - return call(j, val, priority_tag<1> {}); - } -}; - -// taken from ranges-v3 -template<typename T> -struct static_const -{ - static constexpr T value{}; -}; - -template<typename T> -constexpr T static_const<T>::value; -} // namespace detail - - -/// namespace to hold default `to_json` / `from_json` functions -namespace -{ -constexpr const auto& to_json = detail::static_const<detail::to_json_fn>::value; -constexpr const auto& from_json = detail::static_const<detail::from_json_fn>::value; -} - - -/*! -@brief default JSONSerializer template argument - -This serializer ignores the template arguments and uses ADL -([argument-dependent lookup](http://en.cppreference.com/w/cpp/language/adl)) -for serialization. -*/ -template<typename = void, typename = void> -struct adl_serializer -{ - /*! - @brief convert a JSON value to any value type - - This function is usually called by the `get()` function of the - @ref basic_json class (either explicit or via conversion operators). - - @param[in] j JSON value to read from - @param[in,out] val value to write to - */ - template<typename BasicJsonType, typename ValueType> - static void from_json(BasicJsonType&& j, ValueType& val) noexcept( - noexcept(::nlohmann::from_json(std::forward<BasicJsonType>(j), val))) - { - ::nlohmann::from_json(std::forward<BasicJsonType>(j), val); - } - - /*! - @brief convert any value type to a JSON value - - This function is usually called by the constructors of the @ref basic_json - class. - - @param[in,out] j JSON value to write to - @param[in] val value to read from - */ - template<typename BasicJsonType, typename ValueType> - static void to_json(BasicJsonType& j, ValueType&& val) noexcept( - noexcept(::nlohmann::to_json(j, std::forward<ValueType>(val)))) - { - ::nlohmann::to_json(j, std::forward<ValueType>(val)); - } -}; - - -/*! -@brief a class to store JSON values - -@tparam ObjectType type for JSON objects (`std::map` by default; will be used -in @ref object_t) -@tparam ArrayType type for JSON arrays (`std::vector` by default; will be used -in @ref array_t) -@tparam StringType type for JSON strings and object keys (`std::string` by -default; will be used in @ref string_t) -@tparam BooleanType type for JSON booleans (`bool` by default; will be used -in @ref boolean_t) -@tparam NumberIntegerType type for JSON integer numbers (`int64_t` by -default; will be used in @ref number_integer_t) -@tparam NumberUnsignedType type for JSON unsigned integer numbers (@c -`uint64_t` by default; will be used in @ref number_unsigned_t) -@tparam NumberFloatType type for JSON floating-point numbers (`double` by -default; will be used in @ref number_float_t) -@tparam AllocatorType type of the allocator to use (`std::allocator` by -default) -@tparam JSONSerializer the serializer to resolve internal calls to `to_json()` -and `from_json()` (@ref adl_serializer by default) - -@requirement The class satisfies the following concept requirements: -- Basic - - [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible): - JSON values can be default constructed. The result will be a JSON null - value. - - [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible): - A JSON value can be constructed from an rvalue argument. - - [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible): - A JSON value can be copy-constructed from an lvalue expression. - - [MoveAssignable](http://en.cppreference.com/w/cpp/concept/MoveAssignable): - A JSON value van be assigned from an rvalue argument. - - [CopyAssignable](http://en.cppreference.com/w/cpp/concept/CopyAssignable): - A JSON value can be copy-assigned from an lvalue expression. - - [Destructible](http://en.cppreference.com/w/cpp/concept/Destructible): - JSON values can be destructed. -- Layout - - [StandardLayoutType](http://en.cppreference.com/w/cpp/concept/StandardLayoutType): - JSON values have - [standard layout](http://en.cppreference.com/w/cpp/language/data_members#Standard_layout): - All non-static data members are private and standard layout types, the - class has no virtual functions or (virtual) base classes. -- Library-wide - - [EqualityComparable](http://en.cppreference.com/w/cpp/concept/EqualityComparable): - JSON values can be compared with `==`, see @ref - operator==(const_reference,const_reference). - - [LessThanComparable](http://en.cppreference.com/w/cpp/concept/LessThanComparable): - JSON values can be compared with `<`, see @ref - operator<(const_reference,const_reference). - - [Swappable](http://en.cppreference.com/w/cpp/concept/Swappable): - Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of - other compatible types, using unqualified function call @ref swap(). - - [NullablePointer](http://en.cppreference.com/w/cpp/concept/NullablePointer): - JSON values can be compared against `std::nullptr_t` objects which are used - to model the `null` value. -- Container - - [Container](http://en.cppreference.com/w/cpp/concept/Container): - JSON values can be used like STL containers and provide iterator access. - - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer); - JSON values can be used like STL containers and provide reverse iterator - access. - -@invariant The member variables @a m_value and @a m_type have the following -relationship: -- If `m_type == value_t::object`, then `m_value.object != nullptr`. -- If `m_type == value_t::array`, then `m_value.array != nullptr`. -- If `m_type == value_t::string`, then `m_value.string != nullptr`. -The invariants are checked by member function assert_invariant(). - -@internal -@note ObjectType trick from http://stackoverflow.com/a/9860911 -@endinternal - -@see [RFC 7159: The JavaScript Object Notation (JSON) Data Interchange -Format](http://rfc7159.net/rfc7159) - -@since version 1.0.0 - -@nosubgrouping -*/ -template < - template<typename U, typename V, typename... Args> class ObjectType = std::map, - template<typename U, typename... Args> class ArrayType = std::vector, - class StringType = std::string, - class BooleanType = bool, - class NumberIntegerType = std::int64_t, - class NumberUnsignedType = std::uint64_t, - class NumberFloatType = double, - template<typename U> class AllocatorType = std::allocator, - template<typename T, typename SFINAE = void> class JSONSerializer = adl_serializer - > -class basic_json -{ - private: - template<detail::value_t> friend struct detail::external_constructor; - /// workaround type for MSVC - using basic_json_t = basic_json<ObjectType, ArrayType, StringType, - BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, - AllocatorType, JSONSerializer>; - - public: - using value_t = detail::value_t; - // forward declarations - template<typename U> class iter_impl; - template<typename Base> class json_reverse_iterator; - class json_pointer; - template<typename T, typename SFINAE> - using json_serializer = JSONSerializer<T, SFINAE>; - - ///////////////////// - // container types // - ///////////////////// - - /// @name container types - /// The canonic container types to use @ref basic_json like any other STL - /// container. - /// @{ - - /// the type of elements in a basic_json container - using value_type = basic_json; - - /// the type of an element reference - using reference = value_type&; - /// the type of an element const reference - using const_reference = const value_type&; - - /// a type to represent differences between iterators - using difference_type = std::ptrdiff_t; - /// a type to represent container sizes - using size_type = std::size_t; - - /// the allocator type - using allocator_type = AllocatorType<basic_json>; - - /// the type of an element pointer - using pointer = typename std::allocator_traits<allocator_type>::pointer; - /// the type of an element const pointer - using const_pointer = typename std::allocator_traits<allocator_type>::const_pointer; - - /// an iterator for a basic_json container - using iterator = iter_impl<basic_json>; - /// a const iterator for a basic_json container - using const_iterator = iter_impl<const basic_json>; - /// a reverse iterator for a basic_json container - using reverse_iterator = json_reverse_iterator<typename basic_json::iterator>; - /// a const reverse iterator for a basic_json container - using const_reverse_iterator = json_reverse_iterator<typename basic_json::const_iterator>; - - /// @} - - - /*! - @brief returns the allocator associated with the container - */ - static allocator_type get_allocator() - { - return allocator_type(); - } - - /*! - @brief returns version information on the library - - This function returns a JSON object with information about the library, - including the version number and information on the platform and compiler. - - @return JSON object holding version information - key | description - ----------- | --------------- - `compiler` | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version). - `copyright` | The copyright line for the library as string. - `name` | The name of the library as string. - `platform` | The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`. - `url` | The URL of the project as string. - `version` | The version of the library. It is an object with the following keys: `major`, `minor`, and `patch` as defined by [Semantic Versioning](http://semver.org), and `string` (the version string). - - @liveexample{The following code shows an example output of the `meta()` - function.,meta} - - @complexity Constant. - - @since 2.1.0 - */ - static basic_json meta() - { - basic_json result; - - result["copyright"] = "(C) 2013-2017 Niels Lohmann"; - result["name"] = "JSON for Modern C++"; - result["url"] = "https://github.com/nlohmann/json"; - result["version"] = - { - {"string", "2.1.1"}, - {"major", 2}, - {"minor", 1}, - {"patch", 1} - }; - -#ifdef _WIN32 - result["platform"] = "win32"; -#elif defined __linux__ - result["platform"] = "linux"; -#elif defined __APPLE__ - result["platform"] = "apple"; -#elif defined __unix__ - result["platform"] = "unix"; -#else - result["platform"] = "unknown"; -#endif - -#if defined(__clang__) - result["compiler"] = {{"family", "clang"}, {"version", __clang_version__}}; -#elif defined(__ICC) || defined(__INTEL_COMPILER) - result["compiler"] = {{"family", "icc"}, {"version", __INTEL_COMPILER}}; -#elif defined(__GNUC__) || defined(__GNUG__) - result["compiler"] = {{"family", "gcc"}, {"version", std::to_string(__GNUC__) + "." + std::to_string(__GNUC_MINOR__) + "." + std::to_string(__GNUC_PATCHLEVEL__)}}; -#elif defined(__HP_cc) || defined(__HP_aCC) - result["compiler"] = "hp" -#elif defined(__IBMCPP__) - result["compiler"] = {{"family", "ilecpp"}, {"version", __IBMCPP__}}; -#elif defined(_MSC_VER) - result["compiler"] = {{"family", "msvc"}, {"version", _MSC_VER}}; -#elif defined(__PGI) - result["compiler"] = {{"family", "pgcpp"}, {"version", __PGI}}; -#elif defined(__SUNPRO_CC) - result["compiler"] = {{"family", "sunpro"}, {"version", __SUNPRO_CC}}; -#else - result["compiler"] = {{"family", "unknown"}, {"version", "unknown"}}; -#endif - -#ifdef __cplusplus - result["compiler"]["c++"] = std::to_string(__cplusplus); -#else - result["compiler"]["c++"] = "unknown"; -#endif - return result; - } - - - /////////////////////////// - // JSON value data types // - /////////////////////////// - - /// @name JSON value data types - /// The data types to store a JSON value. These types are derived from - /// the template arguments passed to class @ref basic_json. - /// @{ - - /*! - @brief a type for an object - - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows: - > An object is an unordered collection of zero or more name/value pairs, - > where a name is a string and a value is a string, number, boolean, null, - > object, or array. - - To store objects in C++, a type is defined by the template parameters - described below. - - @tparam ObjectType the container to store objects (e.g., `std::map` or - `std::unordered_map`) - @tparam StringType the type of the keys or names (e.g., `std::string`). - The comparison function `std::less<StringType>` is used to order elements - inside the container. - @tparam AllocatorType the allocator to use for objects (e.g., - `std::allocator`) - - #### Default type - - With the default values for @a ObjectType (`std::map`), @a StringType - (`std::string`), and @a AllocatorType (`std::allocator`), the default - value for @a object_t is: - - @code {.cpp} - std::map< - std::string, // key_type - basic_json, // value_type - std::less<std::string>, // key_compare - std::allocator<std::pair<const std::string, basic_json>> // allocator_type - > - @endcode - - #### Behavior - - The choice of @a object_t influences the behavior of the JSON class. With - the default type, objects have the following behavior: - - - When all names are unique, objects will be interoperable in the sense - that all software implementations receiving that object will agree on - the name-value mappings. - - When the names within an object are not unique, later stored name/value - pairs overwrite previously stored name/value pairs, leaving the used - names unique. For instance, `{"key": 1}` and `{"key": 2, "key": 1}` will - be treated as equal and both stored as `{"key": 1}`. - - Internally, name/value pairs are stored in lexicographical order of the - names. Objects will also be serialized (see @ref dump) in this order. - For instance, `{"b": 1, "a": 2}` and `{"a": 2, "b": 1}` will be stored - and serialized as `{"a": 2, "b": 1}`. - - When comparing objects, the order of the name/value pairs is irrelevant. - This makes objects interoperable in the sense that they will not be - affected by these differences. For instance, `{"b": 1, "a": 2}` and - `{"a": 2, "b": 1}` will be treated as equal. - - #### Limits - - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the maximum depth of nesting. - - In this class, the object's limit of nesting is not constraint explicitly. - However, a maximum depth of nesting may be introduced by the compiler or - runtime environment. A theoretical limit can be queried by calling the - @ref max_size function of a JSON object. - - #### Storage - - Objects are stored as pointers in a @ref basic_json type. That is, for any - access to object values, a pointer of type `object_t*` must be - dereferenced. - - @sa @ref array_t -- type for an array value - - @since version 1.0.0 - - @note The order name/value pairs are added to the object is *not* - preserved by the library. Therefore, iterating an object may return - name/value pairs in a different order than they were originally stored. In - fact, keys will be traversed in alphabetical order as `std::map` with - `std::less` is used by default. Please note this behavior conforms to [RFC - 7159](http://rfc7159.net/rfc7159), because any order implements the - specified "unordered" nature of JSON objects. - */ - using object_t = ObjectType<StringType, - basic_json, - std::less<StringType>, - AllocatorType<std::pair<const StringType, - basic_json>>>; - - /*! - @brief a type for an array - - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows: - > An array is an ordered sequence of zero or more values. - - To store objects in C++, a type is defined by the template parameters - explained below. - - @tparam ArrayType container type to store arrays (e.g., `std::vector` or - `std::list`) - @tparam AllocatorType allocator to use for arrays (e.g., `std::allocator`) - - #### Default type - - With the default values for @a ArrayType (`std::vector`) and @a - AllocatorType (`std::allocator`), the default value for @a array_t is: - - @code {.cpp} - std::vector< - basic_json, // value_type - std::allocator<basic_json> // allocator_type - > - @endcode - - #### Limits - - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the maximum depth of nesting. - - In this class, the array's limit of nesting is not constraint explicitly. - However, a maximum depth of nesting may be introduced by the compiler or - runtime environment. A theoretical limit can be queried by calling the - @ref max_size function of a JSON array. - - #### Storage - - Arrays are stored as pointers in a @ref basic_json type. That is, for any - access to array values, a pointer of type `array_t*` must be dereferenced. - - @sa @ref object_t -- type for an object value - - @since version 1.0.0 - */ - using array_t = ArrayType<basic_json, AllocatorType<basic_json>>; - - /*! - @brief a type for a string - - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows: - > A string is a sequence of zero or more Unicode characters. - - To store objects in C++, a type is defined by the template parameter - described below. Unicode values are split by the JSON class into - byte-sized characters during deserialization. - - @tparam StringType the container to store strings (e.g., `std::string`). - Note this container is used for keys/names in objects, see @ref object_t. - - #### Default type - - With the default values for @a StringType (`std::string`), the default - value for @a string_t is: - - @code {.cpp} - std::string - @endcode - - #### Encoding - - Strings are stored in UTF-8 encoding. Therefore, functions like - `std::string::size()` or `std::string::length()` return the number of - bytes in the string rather than the number of characters or glyphs. - - #### String comparison - - [RFC 7159](http://rfc7159.net/rfc7159) states: - > Software implementations are typically required to test names of object - > members for equality. Implementations that transform the textual - > representation into sequences of Unicode code units and then perform the - > comparison numerically, code unit by code unit, are interoperable in the - > sense that implementations will agree in all cases on equality or - > inequality of two strings. For example, implementations that compare - > strings with escaped characters unconverted may incorrectly find that - > `"a\\b"` and `"a\u005Cb"` are not equal. - - This implementation is interoperable as it does compare strings code unit - by code unit. - - #### Storage - - String values are stored as pointers in a @ref basic_json type. That is, - for any access to string values, a pointer of type `string_t*` must be - dereferenced. - - @since version 1.0.0 - */ - using string_t = StringType; - - /*! - @brief a type for a boolean - - [RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a - type which differentiates the two literals `true` and `false`. - - To store objects in C++, a type is defined by the template parameter @a - BooleanType which chooses the type to use. - - #### Default type - - With the default values for @a BooleanType (`bool`), the default value for - @a boolean_t is: - - @code {.cpp} - bool - @endcode - - #### Storage - - Boolean values are stored directly inside a @ref basic_json type. - - @since version 1.0.0 - */ - using boolean_t = BooleanType; - - /*! - @brief a type for a number (integer) - - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. - - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. - - To store integer numbers in C++, a type is defined by the template - parameter @a NumberIntegerType which chooses the type to use. - - #### Default type - - With the default values for @a NumberIntegerType (`int64_t`), the default - value for @a number_integer_t is: - - @code {.cpp} - int64_t - @endcode - - #### Default behavior - - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in integer literals lead to an interpretation as octal - number. Internally, the value will be stored as decimal number. For - instance, the C++ integer literal `010` will be serialized to `8`. - During deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. - - #### Limits - - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the range and precision of numbers. - - When the default type is used, the maximal integer number that can be - stored is `9223372036854775807` (INT64_MAX) and the minimal integer number - that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers - that are out of range will yield over/underflow when used in a - constructor. During deserialization, too large or small integer numbers - will be automatically be stored as @ref number_unsigned_t or @ref - number_float_t. - - [RFC 7159](http://rfc7159.net/rfc7159) further states: - > Note that when such software is used, numbers that are integers and are - > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense - > that implementations will agree exactly on their numeric values. - - As this range is a subrange of the exactly supported range [INT64_MIN, - INT64_MAX], this class's integer type is interoperable. - - #### Storage - - Integer number values are stored directly inside a @ref basic_json type. - - @sa @ref number_float_t -- type for number values (floating-point) - - @sa @ref number_unsigned_t -- type for number values (unsigned integer) - - @since version 1.0.0 - */ - using number_integer_t = NumberIntegerType; - - /*! - @brief a type for a number (unsigned) - - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. - - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. - - To store unsigned integer numbers in C++, a type is defined by the - template parameter @a NumberUnsignedType which chooses the type to use. - - #### Default type - - With the default values for @a NumberUnsignedType (`uint64_t`), the - default value for @a number_unsigned_t is: - - @code {.cpp} - uint64_t - @endcode - - #### Default behavior - - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in integer literals lead to an interpretation as octal - number. Internally, the value will be stored as decimal number. For - instance, the C++ integer literal `010` will be serialized to `8`. - During deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. - - #### Limits - - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the range and precision of numbers. - - When the default type is used, the maximal integer number that can be - stored is `18446744073709551615` (UINT64_MAX) and the minimal integer - number that can be stored is `0`. Integer numbers that are out of range - will yield over/underflow when used in a constructor. During - deserialization, too large or small integer numbers will be automatically - be stored as @ref number_integer_t or @ref number_float_t. - - [RFC 7159](http://rfc7159.net/rfc7159) further states: - > Note that when such software is used, numbers that are integers and are - > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense - > that implementations will agree exactly on their numeric values. - - As this range is a subrange (when considered in conjunction with the - number_integer_t type) of the exactly supported range [0, UINT64_MAX], - this class's integer type is interoperable. - - #### Storage - - Integer number values are stored directly inside a @ref basic_json type. - - @sa @ref number_float_t -- type for number values (floating-point) - @sa @ref number_integer_t -- type for number values (integer) - - @since version 2.0.0 - */ - using number_unsigned_t = NumberUnsignedType; - - /*! - @brief a type for a number (floating-point) - - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. - - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. - - To store floating-point numbers in C++, a type is defined by the template - parameter @a NumberFloatType which chooses the type to use. - - #### Default type - - With the default values for @a NumberFloatType (`double`), the default - value for @a number_float_t is: - - @code {.cpp} - double - @endcode - - #### Default behavior - - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in floating-point literals will be ignored. Internally, - the value will be stored as decimal number. For instance, the C++ - floating-point literal `01.2` will be serialized to `1.2`. During - deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. - - #### Limits - - [RFC 7159](http://rfc7159.net/rfc7159) states: - > This specification allows implementations to set limits on the range and - > precision of numbers accepted. Since software that implements IEEE - > 754-2008 binary64 (double precision) numbers is generally available and - > widely used, good interoperability can be achieved by implementations - > that expect no more precision or range than these provide, in the sense - > that implementations will approximate JSON numbers within the expected - > precision. - - This implementation does exactly follow this approach, as it uses double - precision floating-point numbers. Note values smaller than - `-1.79769313486232e+308` and values greater than `1.79769313486232e+308` - will be stored as NaN internally and be serialized to `null`. - - #### Storage - - Floating-point number values are stored directly inside a @ref basic_json - type. - - @sa @ref number_integer_t -- type for number values (integer) - - @sa @ref number_unsigned_t -- type for number values (unsigned integer) - - @since version 1.0.0 - */ - using number_float_t = NumberFloatType; - - /// @} - - private: - - /// helper for exception-safe object creation - template<typename T, typename... Args> - static T* create(Args&& ... args) - { - AllocatorType<T> alloc; - auto deleter = [&](T * object) - { - alloc.deallocate(object, 1); - }; - std::unique_ptr<T, decltype(deleter)> object(alloc.allocate(1), deleter); - alloc.construct(object.get(), std::forward<Args>(args)...); - assert(object != nullptr); - return object.release(); - } - - //////////////////////// - // JSON value storage // - //////////////////////// - - /*! - @brief a JSON value - - The actual storage for a JSON value of the @ref basic_json class. This - union combines the different storage types for the JSON value types - defined in @ref value_t. - - JSON type | value_t type | used type - --------- | --------------- | ------------------------ - object | object | pointer to @ref object_t - array | array | pointer to @ref array_t - string | string | pointer to @ref string_t - boolean | boolean | @ref boolean_t - number | number_integer | @ref number_integer_t - number | number_unsigned | @ref number_unsigned_t - number | number_float | @ref number_float_t - null | null | *no value is stored* - - @note Variable-length types (objects, arrays, and strings) are stored as - pointers. The size of the union should not exceed 64 bits if the default - value types are used. - - @since version 1.0.0 - */ - union json_value - { - /// object (stored with pointer to save storage) - object_t* object; - /// array (stored with pointer to save storage) - array_t* array; - /// string (stored with pointer to save storage) - string_t* string; - /// boolean - boolean_t boolean; - /// number (integer) - number_integer_t number_integer; - /// number (unsigned integer) - number_unsigned_t number_unsigned; - /// number (floating-point) - number_float_t number_float; - - /// default constructor (for null values) - json_value() = default; - /// constructor for booleans - json_value(boolean_t v) noexcept : boolean(v) {} - /// constructor for numbers (integer) - json_value(number_integer_t v) noexcept : number_integer(v) {} - /// constructor for numbers (unsigned) - json_value(number_unsigned_t v) noexcept : number_unsigned(v) {} - /// constructor for numbers (floating-point) - json_value(number_float_t v) noexcept : number_float(v) {} - /// constructor for empty values of a given type - json_value(value_t t) - { - switch (t) - { - case value_t::object: - { - object = create<object_t>(); - break; - } - - case value_t::array: - { - array = create<array_t>(); - break; - } - - case value_t::string: - { - string = create<string_t>(""); - break; - } - - case value_t::boolean: - { - boolean = boolean_t(false); - break; - } - - case value_t::number_integer: - { - number_integer = number_integer_t(0); - break; - } - - case value_t::number_unsigned: - { - number_unsigned = number_unsigned_t(0); - break; - } - - case value_t::number_float: - { - number_float = number_float_t(0.0); - break; - } - - case value_t::null: - { - break; - } - - default: - { - if (t == value_t::null) - { - JSON_THROW(std::domain_error("961c151d2e87f2686a955a9be24d316f1362bf21 2.1.1")); // LCOV_EXCL_LINE - } - break; - } - } - } - - /// constructor for strings - json_value(const string_t& value) - { - string = create<string_t>(value); - } - - /// constructor for objects - json_value(const object_t& value) - { - object = create<object_t>(value); - } - - /// constructor for arrays - json_value(const array_t& value) - { - array = create<array_t>(value); - } - }; - - /*! - @brief checks the class invariants - - This function asserts the class invariants. It needs to be called at the - end of every constructor to make sure that created objects respect the - invariant. Furthermore, it has to be called each time the type of a JSON - value is changed, because the invariant expresses a relationship between - @a m_type and @a m_value. - */ - void assert_invariant() const - { - assert(m_type != value_t::object or m_value.object != nullptr); - assert(m_type != value_t::array or m_value.array != nullptr); - assert(m_type != value_t::string or m_value.string != nullptr); - } - - public: - ////////////////////////// - // JSON parser callback // - ////////////////////////// - - /*! - @brief JSON callback events - - This enumeration lists the parser events that can trigger calling a - callback function of type @ref parser_callback_t during parsing. - - @image html callback_events.png "Example when certain parse events are triggered" - - @since version 1.0.0 - */ - enum class parse_event_t : uint8_t - { - /// the parser read `{` and started to process a JSON object - object_start, - /// the parser read `}` and finished processing a JSON object - object_end, - /// the parser read `[` and started to process a JSON array - array_start, - /// the parser read `]` and finished processing a JSON array - array_end, - /// the parser read a key of a value in an object - key, - /// the parser finished reading a JSON value - value - }; - - /*! - @brief per-element parser callback type - - With a parser callback function, the result of parsing a JSON text can be - influenced. When passed to @ref parse(std::istream&, const - parser_callback_t) or @ref parse(const CharT, const parser_callback_t), - it is called on certain events (passed as @ref parse_event_t via parameter - @a event) with a set recursion depth @a depth and context JSON value - @a parsed. The return value of the callback function is a boolean - indicating whether the element that emitted the callback shall be kept or - not. - - We distinguish six scenarios (determined by the event type) in which the - callback function can be called. The following table describes the values - of the parameters @a depth, @a event, and @a parsed. - - parameter @a event | description | parameter @a depth | parameter @a parsed - ------------------ | ----------- | ------------------ | ------------------- - parse_event_t::object_start | the parser read `{` and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded - parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key - parse_event_t::object_end | the parser read `}` and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object - parse_event_t::array_start | the parser read `[` and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded - parse_event_t::array_end | the parser read `]` and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array - parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value - - @image html callback_events.png "Example when certain parse events are triggered" - - Discarding a value (i.e., returning `false`) has different effects - depending on the context in which function was called: - - - Discarded values in structured types are skipped. That is, the parser - will behave as if the discarded value was never read. - - In case a value outside a structured type is skipped, it is replaced - with `null`. This case happens if the top-level element is skipped. - - @param[in] depth the depth of the recursion during parsing - - @param[in] event an event of type parse_event_t indicating the context in - the callback function has been called - - @param[in,out] parsed the current intermediate parse result; note that - writing to this value has no effect for parse_event_t::key events - - @return Whether the JSON value which called the function during parsing - should be kept (`true`) or not (`false`). In the latter case, it is either - skipped completely or replaced by an empty discarded object. - - @sa @ref parse(std::istream&, parser_callback_t) or - @ref parse(const CharT, const parser_callback_t) for examples - - @since version 1.0.0 - */ - using parser_callback_t = std::function<bool(int depth, - parse_event_t event, - basic_json& parsed)>; - - - ////////////////// - // constructors // - ////////////////// - - /// @name constructors and destructors - /// Constructors of class @ref basic_json, copy/move constructor, copy - /// assignment, static functions creating objects, and the destructor. - /// @{ - - /*! - @brief create an empty value with a given type - - Create an empty JSON value with a given type. The value will be default - initialized with an empty value which depends on the type: - - Value type | initial value - ----------- | ------------- - null | `null` - boolean | `false` - string | `""` - number | `0` - object | `{}` - array | `[]` - - @param[in] value_type the type of the value to create - - @complexity Constant. - - @throw std::bad_alloc if allocation for object, array, or string value - fails - - @liveexample{The following code shows the constructor for different @ref - value_t values,basic_json__value_t} - - @since version 1.0.0 - */ - basic_json(const value_t value_type) - : m_type(value_type), m_value(value_type) - { - assert_invariant(); - } - - /*! - @brief create a null object - - Create a `null` JSON value. It either takes a null pointer as parameter - (explicitly creating `null`) or no parameter (implicitly creating `null`). - The passed null pointer itself is not read -- it is only used to choose - the right constructor. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this constructor never throws - exceptions. - - @liveexample{The following code shows the constructor with and without a - null pointer parameter.,basic_json__nullptr_t} - - @since version 1.0.0 - */ - basic_json(std::nullptr_t = nullptr) noexcept - : basic_json(value_t::null) - { - assert_invariant(); - } - - /*! - @brief create a JSON value - - This is a "catch all" constructor for all compatible JSON types; that is, - types for which a `to_json()` method exsits. The constructor forwards the - parameter @a val to that method (to `json_serializer<U>::to_json` method - with `U = uncvref_t<CompatibleType>`, to be exact). - - Template type @a CompatibleType includes, but is not limited to, the - following types: - - **arrays**: @ref array_t and all kinds of compatible containers such as - `std::vector`, `std::deque`, `std::list`, `std::forward_list`, - `std::array`, `std::set`, `std::unordered_set`, `std::multiset`, and - `unordered_multiset` with a `value_type` from which a @ref basic_json - value can be constructed. - - **objects**: @ref object_t and all kinds of compatible associative - containers such as `std::map`, `std::unordered_map`, `std::multimap`, - and `std::unordered_multimap` with a `key_type` compatible to - @ref string_t and a `value_type` from which a @ref basic_json value can - be constructed. - - **strings**: @ref string_t, string literals, and all compatible string - containers can be used. - - **numbers**: @ref number_integer_t, @ref number_unsigned_t, - @ref number_float_t, and all convertible number types such as `int`, - `size_t`, `int64_t`, `float` or `double` can be used. - - **boolean**: @ref boolean_t / `bool` can be used. - - See the examples below. - - @tparam CompatibleType a type such that: - - @a CompatibleType is not derived from `std::istream`, - - @a CompatibleType is not @ref basic_json (to avoid hijacking copy/move - constructors), - - @a CompatibleType is not a @ref basic_json nested type (e.g., - @ref json_pointer, @ref iterator, etc ...) - - @ref @ref json_serializer<U> has a - `to_json(basic_json_t&, CompatibleType&&)` method - - @tparam U = `uncvref_t<CompatibleType>` - - @param[in] val the value to be forwarded - - @complexity Usually linear in the size of the passed @a val, also - depending on the implementation of the called `to_json()` - method. - - @throw what `json_serializer<U>::to_json()` throws - - @liveexample{The following code shows the constructor with several - compatible types.,basic_json__CompatibleType} - - @since version 2.1.0 - */ - template<typename CompatibleType, typename U = detail::uncvref_t<CompatibleType>, - detail::enable_if_t<not std::is_base_of<std::istream, U>::value and - not std::is_same<U, basic_json_t>::value and - not detail::is_basic_json_nested_type< - basic_json_t, U>::value and - detail::has_to_json<basic_json, U>::value, - int> = 0> - basic_json(CompatibleType && val) noexcept(noexcept(JSONSerializer<U>::to_json( - std::declval<basic_json_t&>(), std::forward<CompatibleType>(val)))) - { - JSONSerializer<U>::to_json(*this, std::forward<CompatibleType>(val)); - assert_invariant(); - } - - /*! - @brief create a container (array or object) from an initializer list - - Creates a JSON value of type array or object from the passed initializer - list @a init. In case @a type_deduction is `true` (default), the type of - the JSON value to be created is deducted from the initializer list @a init - according to the following rules: - - 1. If the list is empty, an empty JSON object value `{}` is created. - 2. If the list consists of pairs whose first element is a string, a JSON - object value is created where the first elements of the pairs are - treated as keys and the second elements are as values. - 3. In all other cases, an array is created. - - The rules aim to create the best fit between a C++ initializer list and - JSON values. The rationale is as follows: - - 1. The empty initializer list is written as `{}` which is exactly an empty - JSON object. - 2. C++ has now way of describing mapped types other than to list a list of - pairs. As JSON requires that keys must be of type string, rule 2 is the - weakest constraint one can pose on initializer lists to interpret them - as an object. - 3. In all other cases, the initializer list could not be interpreted as - JSON object type, so interpreting it as JSON array type is safe. - - With the rules described above, the following JSON values cannot be - expressed by an initializer list: - - - the empty array (`[]`): use @ref array(std::initializer_list<basic_json>) - with an empty initializer list in this case - - arrays whose elements satisfy rule 2: use @ref - array(std::initializer_list<basic_json>) with the same initializer list - in this case - - @note When used without parentheses around an empty initializer list, @ref - basic_json() is called instead of this function, yielding the JSON null - value. - - @param[in] init initializer list with JSON values - - @param[in] type_deduction internal parameter; when set to `true`, the type - of the JSON value is deducted from the initializer list @a init; when set - to `false`, the type provided via @a manual_type is forced. This mode is - used by the functions @ref array(std::initializer_list<basic_json>) and - @ref object(std::initializer_list<basic_json>). - - @param[in] manual_type internal parameter; when @a type_deduction is set - to `false`, the created JSON value will use the provided type (only @ref - value_t::array and @ref value_t::object are valid); when @a type_deduction - is set to `true`, this parameter has no effect - - @throw std::domain_error if @a type_deduction is `false`, @a manual_type - is `value_t::object`, but @a init contains an element which is not a pair - whose first element is a string; example: `"cannot create object from - initializer list"` - - @complexity Linear in the size of the initializer list @a init. - - @liveexample{The example below shows how JSON values are created from - initializer lists.,basic_json__list_init_t} - - @sa @ref array(std::initializer_list<basic_json>) -- create a JSON array - value from an initializer list - @sa @ref object(std::initializer_list<basic_json>) -- create a JSON object - value from an initializer list - - @since version 1.0.0 - */ - basic_json(std::initializer_list<basic_json> init, - bool type_deduction = true, - value_t manual_type = value_t::array) - { - // check if each element is an array with two elements whose first - // element is a string - bool is_an_object = std::all_of(init.begin(), init.end(), - [](const basic_json & element) - { - return element.is_array() and element.size() == 2 and element[0].is_string(); - }); - - // adjust type if type deduction is not wanted - if (not type_deduction) - { - // if array is wanted, do not create an object though possible - if (manual_type == value_t::array) - { - is_an_object = false; - } - - // if object is wanted but impossible, throw an exception - if (manual_type == value_t::object and not is_an_object) - { - JSON_THROW(std::domain_error("cannot create object from initializer list")); - } - } - - if (is_an_object) - { - // the initializer list is a list of pairs -> create object - m_type = value_t::object; - m_value = value_t::object; - - std::for_each(init.begin(), init.end(), [this](const basic_json & element) - { - m_value.object->emplace(*(element[0].m_value.string), element[1]); - }); - } - else - { - // the initializer list describes an array -> create array - m_type = value_t::array; - m_value.array = create<array_t>(init); - } - - assert_invariant(); - } - - /*! - @brief explicitly create an array from an initializer list - - Creates a JSON array value from a given initializer list. That is, given a - list of values `a, b, c`, creates the JSON value `[a, b, c]`. If the - initializer list is empty, the empty array `[]` is created. - - @note This function is only needed to express two edge cases that cannot - be realized with the initializer list constructor (@ref - basic_json(std::initializer_list<basic_json>, bool, value_t)). These cases - are: - 1. creating an array whose elements are all pairs whose first element is a - string -- in this case, the initializer list constructor would create an - object, taking the first elements as keys - 2. creating an empty array -- passing the empty initializer list to the - initializer list constructor yields an empty object - - @param[in] init initializer list with JSON values to create an array from - (optional) - - @return JSON array value - - @complexity Linear in the size of @a init. - - @liveexample{The following code shows an example for the `array` - function.,array} - - @sa @ref basic_json(std::initializer_list<basic_json>, bool, value_t) -- - create a JSON value from an initializer list - @sa @ref object(std::initializer_list<basic_json>) -- create a JSON object - value from an initializer list - - @since version 1.0.0 - */ - static basic_json array(std::initializer_list<basic_json> init = - std::initializer_list<basic_json>()) - { - return basic_json(init, false, value_t::array); - } - - /*! - @brief explicitly create an object from an initializer list - - Creates a JSON object value from a given initializer list. The initializer - lists elements must be pairs, and their first elements must be strings. If - the initializer list is empty, the empty object `{}` is created. - - @note This function is only added for symmetry reasons. In contrast to the - related function @ref array(std::initializer_list<basic_json>), there are - no cases which can only be expressed by this function. That is, any - initializer list @a init can also be passed to the initializer list - constructor @ref basic_json(std::initializer_list<basic_json>, bool, - value_t). - - @param[in] init initializer list to create an object from (optional) - - @return JSON object value - - @throw std::domain_error if @a init is not a pair whose first elements are - strings; thrown by - @ref basic_json(std::initializer_list<basic_json>, bool, value_t) - - @complexity Linear in the size of @a init. - - @liveexample{The following code shows an example for the `object` - function.,object} - - @sa @ref basic_json(std::initializer_list<basic_json>, bool, value_t) -- - create a JSON value from an initializer list - @sa @ref array(std::initializer_list<basic_json>) -- create a JSON array - value from an initializer list - - @since version 1.0.0 - */ - static basic_json object(std::initializer_list<basic_json> init = - std::initializer_list<basic_json>()) - { - return basic_json(init, false, value_t::object); - } - - /*! - @brief construct an array with count copies of given value - - Constructs a JSON array value by creating @a cnt copies of a passed value. - In case @a cnt is `0`, an empty array is created. As postcondition, - `std::distance(begin(),end()) == cnt` holds. - - @param[in] cnt the number of JSON copies of @a val to create - @param[in] val the JSON value to copy - - @complexity Linear in @a cnt. - - @liveexample{The following code shows examples for the @ref - basic_json(size_type\, const basic_json&) - constructor.,basic_json__size_type_basic_json} - - @since version 1.0.0 - */ - basic_json(size_type cnt, const basic_json& val) - : m_type(value_t::array) - { - m_value.array = create<array_t>(cnt, val); - assert_invariant(); - } - - /*! - @brief construct a JSON container given an iterator range - - Constructs the JSON value with the contents of the range `[first, last)`. - The semantics depends on the different types a JSON value can have: - - In case of primitive types (number, boolean, or string), @a first must - be `begin()` and @a last must be `end()`. In this case, the value is - copied. Otherwise, std::out_of_range is thrown. - - In case of structured types (array, object), the constructor behaves as - similar versions for `std::vector`. - - In case of a null type, std::domain_error is thrown. - - @tparam InputIT an input iterator type (@ref iterator or @ref - const_iterator) - - @param[in] first begin of the range to copy from (included) - @param[in] last end of the range to copy from (excluded) - - @pre Iterators @a first and @a last must be initialized. **This - precondition is enforced with an assertion.** - - @throw std::domain_error if iterators are not compatible; that is, do not - belong to the same JSON value; example: `"iterators are not compatible"` - @throw std::out_of_range if iterators are for a primitive type (number, - boolean, or string) where an out of range error can be detected easily; - example: `"iterators out of range"` - @throw std::bad_alloc if allocation for object, array, or string fails - @throw std::domain_error if called with a null value; example: `"cannot - use construct with iterators from null"` - - @complexity Linear in distance between @a first and @a last. - - @liveexample{The example below shows several ways to create JSON values by - specifying a subrange with iterators.,basic_json__InputIt_InputIt} - - @since version 1.0.0 - */ - template<class InputIT, typename std::enable_if< - std::is_same<InputIT, typename basic_json_t::iterator>::value or - std::is_same<InputIT, typename basic_json_t::const_iterator>::value, int>::type = 0> - basic_json(InputIT first, InputIT last) - { - assert(first.m_object != nullptr); - assert(last.m_object != nullptr); - - // make sure iterator fits the current value - if (first.m_object != last.m_object) - { - JSON_THROW(std::domain_error("iterators are not compatible")); - } - - // copy type from first iterator - m_type = first.m_object->m_type; - - // check if iterator range is complete for primitive values - switch (m_type) - { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: - { - if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end()) - { - JSON_THROW(std::out_of_range("iterators out of range")); - } - break; - } - - default: - { - break; - } - } - - switch (m_type) - { - case value_t::number_integer: - { - m_value.number_integer = first.m_object->m_value.number_integer; - break; - } - - case value_t::number_unsigned: - { - m_value.number_unsigned = first.m_object->m_value.number_unsigned; - break; - } - - case value_t::number_float: - { - m_value.number_float = first.m_object->m_value.number_float; - break; - } - - case value_t::boolean: - { - m_value.boolean = first.m_object->m_value.boolean; - break; - } - - case value_t::string: - { - m_value = *first.m_object->m_value.string; - break; - } - - case value_t::object: - { - m_value.object = create<object_t>(first.m_it.object_iterator, - last.m_it.object_iterator); - break; - } - - case value_t::array: - { - m_value.array = create<array_t>(first.m_it.array_iterator, - last.m_it.array_iterator); - break; - } - - default: - { - JSON_THROW(std::domain_error("cannot use construct with iterators from " + first.m_object->type_name())); - } - } - - assert_invariant(); - } - - /*! - @brief construct a JSON value given an input stream - - @param[in,out] i stream to read a serialized JSON value from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) - - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. - - @note A UTF-8 byte order mark is silently ignored. - - @deprecated This constructor is deprecated and will be removed in version - 3.0.0 to unify the interface of the library. Deserialization will be - done by stream operators or by calling one of the `parse` functions, - e.g. @ref parse(std::istream&, const parser_callback_t). That is, calls - like `json j(i);` for an input stream @a i need to be replaced by - `json j = json::parse(i);`. See the example below. - - @liveexample{The example below demonstrates constructing a JSON value from - a `std::stringstream` with and without callback - function.,basic_json__istream} - - @since version 2.0.0, deprecated in version 2.0.3, to be removed in - version 3.0.0 - */ - JSON_DEPRECATED - explicit basic_json(std::istream& i, const parser_callback_t cb = nullptr) - { - *this = parser(i, cb).parse(); - assert_invariant(); - } - - /////////////////////////////////////// - // other constructors and destructor // - /////////////////////////////////////// - - /*! - @brief copy constructor - - Creates a copy of a given JSON value. - - @param[in] other the JSON value to copy - - @complexity Linear in the size of @a other. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - As postcondition, it holds: `other == basic_json(other)`. - - @throw std::bad_alloc if allocation for object, array, or string fails. - - @liveexample{The following code shows an example for the copy - constructor.,basic_json__basic_json} - - @since version 1.0.0 - */ - basic_json(const basic_json& other) - : m_type(other.m_type) - { - // check of passed value is valid - other.assert_invariant(); - - switch (m_type) - { - case value_t::object: - { - m_value = *other.m_value.object; - break; - } - - case value_t::array: - { - m_value = *other.m_value.array; - break; - } - - case value_t::string: - { - m_value = *other.m_value.string; - break; - } - - case value_t::boolean: - { - m_value = other.m_value.boolean; - break; - } - - case value_t::number_integer: - { - m_value = other.m_value.number_integer; - break; - } - - case value_t::number_unsigned: - { - m_value = other.m_value.number_unsigned; - break; - } - - case value_t::number_float: - { - m_value = other.m_value.number_float; - break; - } - - default: - { - break; - } - } - - assert_invariant(); - } - - /*! - @brief move constructor - - Move constructor. Constructs a JSON value with the contents of the given - value @a other using move semantics. It "steals" the resources from @a - other and leaves it as JSON null value. - - @param[in,out] other value to move to this object - - @post @a other is a JSON null value - - @complexity Constant. - - @liveexample{The code below shows the move constructor explicitly called - via std::move.,basic_json__moveconstructor} - - @since version 1.0.0 - */ - basic_json(basic_json&& other) noexcept - : m_type(std::move(other.m_type)), - m_value(std::move(other.m_value)) - { - // check that passed value is valid - other.assert_invariant(); - - // invalidate payload - other.m_type = value_t::null; - other.m_value = {}; - - assert_invariant(); - } - - /*! - @brief copy assignment - - Copy assignment operator. Copies a JSON value via the "copy and swap" - strategy: It is expressed in terms of the copy constructor, destructor, - and the swap() member function. - - @param[in] other value to copy from - - @complexity Linear. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - @liveexample{The code below shows and example for the copy assignment. It - creates a copy of value `a` which is then swapped with `b`. Finally\, the - copy of `a` (which is the null value after the swap) is - destroyed.,basic_json__copyassignment} - - @since version 1.0.0 - */ - reference& operator=(basic_json other) noexcept ( - std::is_nothrow_move_constructible<value_t>::value and - std::is_nothrow_move_assignable<value_t>::value and - std::is_nothrow_move_constructible<json_value>::value and - std::is_nothrow_move_assignable<json_value>::value - ) - { - // check that passed value is valid - other.assert_invariant(); - - using std::swap; - swap(m_type, other.m_type); - swap(m_value, other.m_value); - - assert_invariant(); - return *this; - } - - /*! - @brief destructor - - Destroys the JSON value and frees all allocated memory. - - @complexity Linear. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - All stored elements are destroyed and all memory is freed. - - @since version 1.0.0 - */ - ~basic_json() - { - assert_invariant(); - - switch (m_type) - { - case value_t::object: - { - AllocatorType<object_t> alloc; - alloc.destroy(m_value.object); - alloc.deallocate(m_value.object, 1); - break; - } - - case value_t::array: - { - AllocatorType<array_t> alloc; - alloc.destroy(m_value.array); - alloc.deallocate(m_value.array, 1); - break; - } - - case value_t::string: - { - AllocatorType<string_t> alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - break; - } - - default: - { - // all other types need no specific destructor - break; - } - } - } - - /// @} - - public: - /////////////////////// - // object inspection // - /////////////////////// - - /// @name object inspection - /// Functions to inspect the type of a JSON value. - /// @{ - - /*! - @brief serialization - - Serialization function for JSON values. The function tries to mimic - Python's `json.dumps()` function, and currently supports its @a indent - parameter. - - @param[in] indent If indent is nonnegative, then array elements and object - members will be pretty-printed with that indent level. An indent level of - `0` will only insert newlines. `-1` (the default) selects the most compact - representation. - - @return string containing the serialization of the JSON value - - @complexity Linear. - - @liveexample{The following example shows the effect of different @a indent - parameters to the result of the serialization.,dump} - - @see https://docs.python.org/2/library/json.html#json.dump - - @since version 1.0.0 - */ - string_t dump(const int indent = -1) const - { - std::stringstream ss; - - if (indent >= 0) - { - dump(ss, true, static_cast<unsigned int>(indent)); - } - else - { - dump(ss, false, 0); - } - - return ss.str(); - } - - /*! - @brief return the type of the JSON value (explicit) - - Return the type of the JSON value as a value from the @ref value_t - enumeration. - - @return the type of the JSON value - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `type()` for all JSON - types.,type} - - @since version 1.0.0 - */ - constexpr value_t type() const noexcept - { - return m_type; - } - - /*! - @brief return whether type is primitive - - This function returns true iff the JSON type is primitive (string, number, - boolean, or null). - - @return `true` if type is primitive (string, number, boolean, or null), - `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_primitive()` for all JSON - types.,is_primitive} - - @sa @ref is_structured() -- returns whether JSON value is structured - @sa @ref is_null() -- returns whether JSON value is `null` - @sa @ref is_string() -- returns whether JSON value is a string - @sa @ref is_boolean() -- returns whether JSON value is a boolean - @sa @ref is_number() -- returns whether JSON value is a number - - @since version 1.0.0 - */ - constexpr bool is_primitive() const noexcept - { - return is_null() or is_string() or is_boolean() or is_number(); - } - - /*! - @brief return whether type is structured - - This function returns true iff the JSON type is structured (array or - object). - - @return `true` if type is structured (array or object), `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_structured()` for all JSON - types.,is_structured} - - @sa @ref is_primitive() -- returns whether value is primitive - @sa @ref is_array() -- returns whether value is an array - @sa @ref is_object() -- returns whether value is an object - - @since version 1.0.0 - */ - constexpr bool is_structured() const noexcept - { - return is_array() or is_object(); - } - - /*! - @brief return whether value is null - - This function returns true iff the JSON value is null. - - @return `true` if type is null, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_null()` for all JSON - types.,is_null} - - @since version 1.0.0 - */ - constexpr bool is_null() const noexcept - { - return m_type == value_t::null; - } - - /*! - @brief return whether value is a boolean - - This function returns true iff the JSON value is a boolean. - - @return `true` if type is boolean, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_boolean()` for all JSON - types.,is_boolean} - - @since version 1.0.0 - */ - constexpr bool is_boolean() const noexcept - { - return m_type == value_t::boolean; - } - - /*! - @brief return whether value is a number - - This function returns true iff the JSON value is a number. This includes - both integer and floating-point values. - - @return `true` if type is number (regardless whether integer, unsigned - integer or floating-type), `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_number()` for all JSON - types.,is_number} - - @sa @ref is_number_integer() -- check if value is an integer or unsigned - integer number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number - @sa @ref is_number_float() -- check if value is a floating-point number - - @since version 1.0.0 - */ - constexpr bool is_number() const noexcept - { - return is_number_integer() or is_number_float(); - } - - /*! - @brief return whether value is an integer number - - This function returns true iff the JSON value is an integer or unsigned - integer number. This excludes floating-point values. - - @return `true` if type is an integer or unsigned integer number, `false` - otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_number_integer()` for all - JSON types.,is_number_integer} - - @sa @ref is_number() -- check if value is a number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number - @sa @ref is_number_float() -- check if value is a floating-point number - - @since version 1.0.0 - */ - constexpr bool is_number_integer() const noexcept - { - return m_type == value_t::number_integer or m_type == value_t::number_unsigned; - } - - /*! - @brief return whether value is an unsigned integer number - - This function returns true iff the JSON value is an unsigned integer - number. This excludes floating-point and (signed) integer values. - - @return `true` if type is an unsigned integer number, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_number_unsigned()` for all - JSON types.,is_number_unsigned} - - @sa @ref is_number() -- check if value is a number - @sa @ref is_number_integer() -- check if value is an integer or unsigned - integer number - @sa @ref is_number_float() -- check if value is a floating-point number - - @since version 2.0.0 - */ - constexpr bool is_number_unsigned() const noexcept - { - return m_type == value_t::number_unsigned; - } - - /*! - @brief return whether value is a floating-point number - - This function returns true iff the JSON value is a floating-point number. - This excludes integer and unsigned integer values. - - @return `true` if type is a floating-point number, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_number_float()` for all - JSON types.,is_number_float} - - @sa @ref is_number() -- check if value is number - @sa @ref is_number_integer() -- check if value is an integer number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number - - @since version 1.0.0 - */ - constexpr bool is_number_float() const noexcept - { - return m_type == value_t::number_float; - } - - /*! - @brief return whether value is an object - - This function returns true iff the JSON value is an object. - - @return `true` if type is object, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_object()` for all JSON - types.,is_object} - - @since version 1.0.0 - */ - constexpr bool is_object() const noexcept - { - return m_type == value_t::object; - } - - /*! - @brief return whether value is an array - - This function returns true iff the JSON value is an array. - - @return `true` if type is array, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_array()` for all JSON - types.,is_array} - - @since version 1.0.0 - */ - constexpr bool is_array() const noexcept - { - return m_type == value_t::array; - } - - /*! - @brief return whether value is a string - - This function returns true iff the JSON value is a string. - - @return `true` if type is string, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_string()` for all JSON - types.,is_string} - - @since version 1.0.0 - */ - constexpr bool is_string() const noexcept - { - return m_type == value_t::string; - } - - /*! - @brief return whether value is discarded - - This function returns true iff the JSON value was discarded during parsing - with a callback function (see @ref parser_callback_t). - - @note This function will always be `false` for JSON values after parsing. - That is, discarded values can only occur during parsing, but will be - removed when inside a structured value or replaced by null in other cases. - - @return `true` if type is discarded, `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_discarded()` for all JSON - types.,is_discarded} - - @since version 1.0.0 - */ - constexpr bool is_discarded() const noexcept - { - return m_type == value_t::discarded; - } - - /*! - @brief return the type of the JSON value (implicit) - - Implicitly return the type of the JSON value as a value from the @ref - value_t enumeration. - - @return the type of the JSON value - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies the @ref value_t operator for - all JSON types.,operator__value_t} - - @since version 1.0.0 - */ - constexpr operator value_t() const noexcept - { - return m_type; - } - - /// @} - - private: - ////////////////// - // value access // - ////////////////// - - /// get a boolean (explicit) - boolean_t get_impl(boolean_t* /*unused*/) const - { - if (is_boolean()) - { - return m_value.boolean; - } - - JSON_THROW(std::domain_error("type must be boolean, but is " + type_name())); - } - - /// get a pointer to the value (object) - object_t* get_impl_ptr(object_t* /*unused*/) noexcept - { - return is_object() ? m_value.object : nullptr; - } - - /// get a pointer to the value (object) - constexpr const object_t* get_impl_ptr(const object_t* /*unused*/) const noexcept - { - return is_object() ? m_value.object : nullptr; - } - - /// get a pointer to the value (array) - array_t* get_impl_ptr(array_t* /*unused*/) noexcept - { - return is_array() ? m_value.array : nullptr; - } - - /// get a pointer to the value (array) - constexpr const array_t* get_impl_ptr(const array_t* /*unused*/) const noexcept - { - return is_array() ? m_value.array : nullptr; - } - - /// get a pointer to the value (string) - string_t* get_impl_ptr(string_t* /*unused*/) noexcept - { - return is_string() ? m_value.string : nullptr; - } - - /// get a pointer to the value (string) - constexpr const string_t* get_impl_ptr(const string_t* /*unused*/) const noexcept - { - return is_string() ? m_value.string : nullptr; - } - - /// get a pointer to the value (boolean) - boolean_t* get_impl_ptr(boolean_t* /*unused*/) noexcept - { - return is_boolean() ? &m_value.boolean : nullptr; - } - - /// get a pointer to the value (boolean) - constexpr const boolean_t* get_impl_ptr(const boolean_t* /*unused*/) const noexcept - { - return is_boolean() ? &m_value.boolean : nullptr; - } - - /// get a pointer to the value (integer number) - number_integer_t* get_impl_ptr(number_integer_t* /*unused*/) noexcept - { - return is_number_integer() ? &m_value.number_integer : nullptr; - } - - /// get a pointer to the value (integer number) - constexpr const number_integer_t* get_impl_ptr(const number_integer_t* /*unused*/) const noexcept - { - return is_number_integer() ? &m_value.number_integer : nullptr; - } - - /// get a pointer to the value (unsigned number) - number_unsigned_t* get_impl_ptr(number_unsigned_t* /*unused*/) noexcept - { - return is_number_unsigned() ? &m_value.number_unsigned : nullptr; - } - - /// get a pointer to the value (unsigned number) - constexpr const number_unsigned_t* get_impl_ptr(const number_unsigned_t* /*unused*/) const noexcept - { - return is_number_unsigned() ? &m_value.number_unsigned : nullptr; - } - - /// get a pointer to the value (floating-point number) - number_float_t* get_impl_ptr(number_float_t* /*unused*/) noexcept - { - return is_number_float() ? &m_value.number_float : nullptr; - } - - /// get a pointer to the value (floating-point number) - constexpr const number_float_t* get_impl_ptr(const number_float_t* /*unused*/) const noexcept - { - return is_number_float() ? &m_value.number_float : nullptr; - } - - /*! - @brief helper function to implement get_ref() - - This funcion helps to implement get_ref() without code duplication for - const and non-const overloads - - @tparam ThisType will be deduced as `basic_json` or `const basic_json` - - @throw std::domain_error if ReferenceType does not match underlying value - type of the current JSON - */ - template<typename ReferenceType, typename ThisType> - static ReferenceType get_ref_impl(ThisType& obj) - { - // helper type - using PointerType = typename std::add_pointer<ReferenceType>::type; - - // delegate the call to get_ptr<>() - auto ptr = obj.template get_ptr<PointerType>(); - - if (ptr != nullptr) - { - return *ptr; - } - - JSON_THROW(std::domain_error("incompatible ReferenceType for get_ref, actual type is " + - obj.type_name())); - } - - public: - /// @name value access - /// Direct access to the stored value of a JSON value. - /// @{ - - /*! - @brief get special-case overload - - This overloads avoids a lot of template boilerplate, it can be seen as the - identity method - - @tparam BasicJsonType == @ref basic_json - - @return a copy of *this - - @complexity Constant. - - @since version 2.1.0 - */ - template < - typename BasicJsonType, - detail::enable_if_t<std::is_same<typename std::remove_const<BasicJsonType>::type, - basic_json_t>::value, - int> = 0 > - basic_json get() const - { - return *this; - } - - /*! - @brief get a value (explicit) - - Explicit type conversion between the JSON value and a compatible value - which is [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) - and [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). - The value is converted by calling the @ref json_serializer<ValueType> - `from_json()` method. - - The function is equivalent to executing - @code {.cpp} - ValueType ret; - JSONSerializer<ValueType>::from_json(*this, ret); - return ret; - @endcode - - This overloads is chosen if: - - @a ValueType is not @ref basic_json, - - @ref json_serializer<ValueType> has a `from_json()` method of the form - `void from_json(const @ref basic_json&, ValueType&)`, and - - @ref json_serializer<ValueType> does not have a `from_json()` method of - the form `ValueType from_json(const @ref basic_json&)` - - @tparam ValueTypeCV the provided value type - @tparam ValueType the returned value type - - @return copy of the JSON value, converted to @a ValueType - - @throw what @ref json_serializer<ValueType> `from_json()` method throws - - @liveexample{The example below shows several conversions from JSON values - to other types. There a few things to note: (1) Floating-point numbers can - be converted to integers\, (2) A JSON array can be converted to a standard - `std::vector<short>`\, (3) A JSON object can be converted to C++ - associative containers such as `std::unordered_map<std::string\, - json>`.,get__ValueType_const} - - @since version 2.1.0 - */ - template < - typename ValueTypeCV, - typename ValueType = detail::uncvref_t<ValueTypeCV>, - detail::enable_if_t < - not std::is_same<basic_json_t, ValueType>::value and - detail::has_from_json<basic_json_t, ValueType>::value and - not detail::has_non_default_from_json<basic_json_t, ValueType>::value, - int > = 0 > - ValueType get() const noexcept(noexcept( - JSONSerializer<ValueType>::from_json(std::declval<const basic_json_t&>(), std::declval<ValueType&>()))) - { - // we cannot static_assert on ValueTypeCV being non-const, because - // there is support for get<const basic_json_t>(), which is why we - // still need the uncvref - static_assert(not std::is_reference<ValueTypeCV>::value, - "get() cannot be used with reference types, you might want to use get_ref()"); - static_assert(std::is_default_constructible<ValueType>::value, - "types must be DefaultConstructible when used with get()"); - - ValueType ret; - JSONSerializer<ValueType>::from_json(*this, ret); - return ret; - } - - /*! - @brief get a value (explicit); special case - - Explicit type conversion between the JSON value and a compatible value - which is **not** [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) - and **not** [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). - The value is converted by calling the @ref json_serializer<ValueType> - `from_json()` method. - - The function is equivalent to executing - @code {.cpp} - return JSONSerializer<ValueTypeCV>::from_json(*this); - @endcode - - This overloads is chosen if: - - @a ValueType is not @ref basic_json and - - @ref json_serializer<ValueType> has a `from_json()` method of the form - `ValueType from_json(const @ref basic_json&)` - - @note If @ref json_serializer<ValueType> has both overloads of - `from_json()`, this one is chosen. - - @tparam ValueTypeCV the provided value type - @tparam ValueType the returned value type - - @return copy of the JSON value, converted to @a ValueType - - @throw what @ref json_serializer<ValueType> `from_json()` method throws - - @since version 2.1.0 - */ - template < - typename ValueTypeCV, - typename ValueType = detail::uncvref_t<ValueTypeCV>, - detail::enable_if_t<not std::is_same<basic_json_t, ValueType>::value and - detail::has_non_default_from_json<basic_json_t, - ValueType>::value, int> = 0 > - ValueType get() const noexcept(noexcept( - JSONSerializer<ValueTypeCV>::from_json(std::declval<const basic_json_t&>()))) - { - static_assert(not std::is_reference<ValueTypeCV>::value, - "get() cannot be used with reference types, you might want to use get_ref()"); - return JSONSerializer<ValueTypeCV>::from_json(*this); - } - - /*! - @brief get a pointer value (explicit) - - Explicit pointer access to the internally stored JSON value. No copies are - made. - - @warning The pointer becomes invalid if the underlying JSON object - changes. - - @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref - object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, - @ref number_unsigned_t, or @ref number_float_t. - - @return pointer to the internally stored JSON value if the requested - pointer type @a PointerType fits to the JSON value; `nullptr` otherwise - - @complexity Constant. - - @liveexample{The example below shows how pointers to internal values of a - JSON value can be requested. Note that no type conversions are made and a - `nullptr` is returned if the value and the requested pointer type does not - match.,get__PointerType} - - @sa @ref get_ptr() for explicit pointer-member access - - @since version 1.0.0 - */ - template<typename PointerType, typename std::enable_if< - std::is_pointer<PointerType>::value, int>::type = 0> - PointerType get() noexcept - { - // delegate the call to get_ptr - return get_ptr<PointerType>(); - } - - /*! - @brief get a pointer value (explicit) - @copydoc get() - */ - template<typename PointerType, typename std::enable_if< - std::is_pointer<PointerType>::value, int>::type = 0> - constexpr const PointerType get() const noexcept - { - // delegate the call to get_ptr - return get_ptr<PointerType>(); - } - - /*! - @brief get a pointer value (implicit) - - Implicit pointer access to the internally stored JSON value. No copies are - made. - - @warning Writing data to the pointee of the result yields an undefined - state. - - @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref - object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, - @ref number_unsigned_t, or @ref number_float_t. Enforced by a static - assertion. - - @return pointer to the internally stored JSON value if the requested - pointer type @a PointerType fits to the JSON value; `nullptr` otherwise - - @complexity Constant. - - @liveexample{The example below shows how pointers to internal values of a - JSON value can be requested. Note that no type conversions are made and a - `nullptr` is returned if the value and the requested pointer type does not - match.,get_ptr} - - @since version 1.0.0 - */ - template<typename PointerType, typename std::enable_if< - std::is_pointer<PointerType>::value, int>::type = 0> - PointerType get_ptr() noexcept - { - // get the type of the PointerType (remove pointer and const) - using pointee_t = typename std::remove_const<typename - std::remove_pointer<typename - std::remove_const<PointerType>::type>::type>::type; - // make sure the type matches the allowed types - static_assert( - std::is_same<object_t, pointee_t>::value - or std::is_same<array_t, pointee_t>::value - or std::is_same<string_t, pointee_t>::value - or std::is_same<boolean_t, pointee_t>::value - or std::is_same<number_integer_t, pointee_t>::value - or std::is_same<number_unsigned_t, pointee_t>::value - or std::is_same<number_float_t, pointee_t>::value - , "incompatible pointer type"); - - // delegate the call to get_impl_ptr<>() - return get_impl_ptr(static_cast<PointerType>(nullptr)); - } - - /*! - @brief get a pointer value (implicit) - @copydoc get_ptr() - */ - template<typename PointerType, typename std::enable_if< - std::is_pointer<PointerType>::value and - std::is_const<typename std::remove_pointer<PointerType>::type>::value, int>::type = 0> - constexpr const PointerType get_ptr() const noexcept - { - // get the type of the PointerType (remove pointer and const) - using pointee_t = typename std::remove_const<typename - std::remove_pointer<typename - std::remove_const<PointerType>::type>::type>::type; - // make sure the type matches the allowed types - static_assert( - std::is_same<object_t, pointee_t>::value - or std::is_same<array_t, pointee_t>::value - or std::is_same<string_t, pointee_t>::value - or std::is_same<boolean_t, pointee_t>::value - or std::is_same<number_integer_t, pointee_t>::value - or std::is_same<number_unsigned_t, pointee_t>::value - or std::is_same<number_float_t, pointee_t>::value - , "incompatible pointer type"); - - // delegate the call to get_impl_ptr<>() const - return get_impl_ptr(static_cast<const PointerType>(nullptr)); - } - - /*! - @brief get a reference value (implicit) - - Implicit reference access to the internally stored JSON value. No copies - are made. - - @warning Writing data to the referee of the result yields an undefined - state. - - @tparam ReferenceType reference type; must be a reference to @ref array_t, - @ref object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or - @ref number_float_t. Enforced by static assertion. - - @return reference to the internally stored JSON value if the requested - reference type @a ReferenceType fits to the JSON value; throws - std::domain_error otherwise - - @throw std::domain_error in case passed type @a ReferenceType is - incompatible with the stored JSON value - - @complexity Constant. - - @liveexample{The example shows several calls to `get_ref()`.,get_ref} - - @since version 1.1.0 - */ - template<typename ReferenceType, typename std::enable_if< - std::is_reference<ReferenceType>::value, int>::type = 0> - ReferenceType get_ref() - { - // delegate call to get_ref_impl - return get_ref_impl<ReferenceType>(*this); - } - - /*! - @brief get a reference value (implicit) - @copydoc get_ref() - */ - template<typename ReferenceType, typename std::enable_if< - std::is_reference<ReferenceType>::value and - std::is_const<typename std::remove_reference<ReferenceType>::type>::value, int>::type = 0> - ReferenceType get_ref() const - { - // delegate call to get_ref_impl - return get_ref_impl<ReferenceType>(*this); - } - - /*! - @brief get a value (implicit) - - Implicit type conversion between the JSON value and a compatible value. - The call is realized by calling @ref get() const. - - @tparam ValueType non-pointer type compatible to the JSON value, for - instance `int` for JSON integer numbers, `bool` for JSON booleans, or - `std::vector` types for JSON arrays. The character type of @ref string_t - as well as an initializer list of this type is excluded to avoid - ambiguities as these types implicitly convert to `std::string`. - - @return copy of the JSON value, converted to type @a ValueType - - @throw std::domain_error in case passed type @a ValueType is incompatible - to JSON, thrown by @ref get() const - - @complexity Linear in the size of the JSON value. - - @liveexample{The example below shows several conversions from JSON values - to other types. There a few things to note: (1) Floating-point numbers can - be converted to integers\, (2) A JSON array can be converted to a standard - `std::vector<short>`\, (3) A JSON object can be converted to C++ - associative containers such as `std::unordered_map<std::string\, - json>`.,operator__ValueType} - - @since version 1.0.0 - */ - template < typename ValueType, typename std::enable_if < - not std::is_pointer<ValueType>::value and - not std::is_same<ValueType, typename string_t::value_type>::value -#ifndef _MSC_VER // fix for issue #167 operator<< ambiguity under VS2015 - and not std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>::value -#endif - , int >::type = 0 > - operator ValueType() const - { - // delegate the call to get<>() const - return get<ValueType>(); - } - - /// @} - - - //////////////////// - // element access // - //////////////////// - - /// @name element access - /// Access to the JSON value. - /// @{ - - /*! - @brief access specified array element with bounds checking - - Returns a reference to the element at specified location @a idx, with - bounds checking. - - @param[in] idx index of the element to access - - @return reference to the element at index @a idx - - @throw std::domain_error if the JSON value is not an array; example: - `"cannot use at() with string"` - @throw std::out_of_range if the index @a idx is out of range of the array; - that is, `idx >= size()`; example: `"array index 7 is out of range"` - - @complexity Constant. - - @liveexample{The example below shows how array elements can be read and - written using `at()`.,at__size_type} - - @since version 1.0.0 - */ - reference at(size_type idx) - { - // at only works for arrays - if (is_array()) - { - JSON_TRY - { - return m_value.array->at(idx); - } - JSON_CATCH (std::out_of_range&) - { - // create better exception explanation - JSON_THROW(std::out_of_range("array index " + std::to_string(idx) + " is out of range")); - } - } - else - { - JSON_THROW(std::domain_error("cannot use at() with " + type_name())); - } - } - - /*! - @brief access specified array element with bounds checking - - Returns a const reference to the element at specified location @a idx, - with bounds checking. - - @param[in] idx index of the element to access - - @return const reference to the element at index @a idx - - @throw std::domain_error if the JSON value is not an array; example: - `"cannot use at() with string"` - @throw std::out_of_range if the index @a idx is out of range of the array; - that is, `idx >= size()`; example: `"array index 7 is out of range"` - - @complexity Constant. - - @liveexample{The example below shows how array elements can be read using - `at()`.,at__size_type_const} - - @since version 1.0.0 - */ - const_reference at(size_type idx) const - { - // at only works for arrays - if (is_array()) - { - JSON_TRY - { - return m_value.array->at(idx); - } - JSON_CATCH (std::out_of_range&) - { - // create better exception explanation - JSON_THROW(std::out_of_range("array index " + std::to_string(idx) + " is out of range")); - } - } - else - { - JSON_THROW(std::domain_error("cannot use at() with " + type_name())); - } - } - - /*! - @brief access specified object element with bounds checking - - Returns a reference to the element at with specified key @a key, with - bounds checking. - - @param[in] key key of the element to access - - @return reference to the element at key @a key - - @throw std::domain_error if the JSON value is not an object; example: - `"cannot use at() with boolean"` - @throw std::out_of_range if the key @a key is is not stored in the object; - that is, `find(key) == end()`; example: `"key "the fast" not found"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read and - written using `at()`.,at__object_t_key_type} - - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @sa @ref value() for access by value with a default value - - @since version 1.0.0 - */ - reference at(const typename object_t::key_type& key) - { - // at only works for objects - if (is_object()) - { - JSON_TRY - { - return m_value.object->at(key); - } - JSON_CATCH (std::out_of_range&) - { - // create better exception explanation - JSON_THROW(std::out_of_range("key '" + key + "' not found")); - } - } - else - { - JSON_THROW(std::domain_error("cannot use at() with " + type_name())); - } - } - - /*! - @brief access specified object element with bounds checking - - Returns a const reference to the element at with specified key @a key, - with bounds checking. - - @param[in] key key of the element to access - - @return const reference to the element at key @a key - - @throw std::domain_error if the JSON value is not an object; example: - `"cannot use at() with boolean"` - @throw std::out_of_range if the key @a key is is not stored in the object; - that is, `find(key) == end()`; example: `"key "the fast" not found"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read using - `at()`.,at__object_t_key_type_const} - - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @sa @ref value() for access by value with a default value - - @since version 1.0.0 - */ - const_reference at(const typename object_t::key_type& key) const - { - // at only works for objects - if (is_object()) - { - JSON_TRY - { - return m_value.object->at(key); - } - JSON_CATCH (std::out_of_range&) - { - // create better exception explanation - JSON_THROW(std::out_of_range("key '" + key + "' not found")); - } - } - else - { - JSON_THROW(std::domain_error("cannot use at() with " + type_name())); - } - } - - /*! - @brief access specified array element - - Returns a reference to the element at specified location @a idx. - - @note If @a idx is beyond the range of the array (i.e., `idx >= size()`), - then the array is silently filled up with `null` values to make `idx` a - valid reference to the last stored element. - - @param[in] idx index of the element to access - - @return reference to the element at index @a idx - - @throw std::domain_error if JSON is not an array or null; example: - `"cannot use operator[] with string"` - - @complexity Constant if @a idx is in the range of the array. Otherwise - linear in `idx - size()`. - - @liveexample{The example below shows how array elements can be read and - written using `[]` operator. Note the addition of `null` - values.,operatorarray__size_type} - - @since version 1.0.0 - */ - reference operator[](size_type idx) - { - // implicitly convert null value to an empty array - if (is_null()) - { - m_type = value_t::array; - m_value.array = create<array_t>(); - assert_invariant(); - } - - // operator[] only works for arrays - if (is_array()) - { - // fill up array with null values if given idx is outside range - if (idx >= m_value.array->size()) - { - m_value.array->insert(m_value.array->end(), - idx - m_value.array->size() + 1, - basic_json()); - } - - return m_value.array->operator[](idx); - } - - JSON_THROW(std::domain_error("cannot use operator[] with " + type_name())); - } - - /*! - @brief access specified array element - - Returns a const reference to the element at specified location @a idx. - - @param[in] idx index of the element to access - - @return const reference to the element at index @a idx - - @throw std::domain_error if JSON is not an array; example: `"cannot use - operator[] with null"` - - @complexity Constant. - - @liveexample{The example below shows how array elements can be read using - the `[]` operator.,operatorarray__size_type_const} - - @since version 1.0.0 - */ - const_reference operator[](size_type idx) const - { - // const operator[] only works for arrays - if (is_array()) - { - return m_value.array->operator[](idx); - } - - JSON_THROW(std::domain_error("cannot use operator[] with " + type_name())); - } - - /*! - @brief access specified object element - - Returns a reference to the element at with specified key @a key. - - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. - - @param[in] key key of the element to access - - @return reference to the element at key @a key - - @throw std::domain_error if JSON is not an object or null; example: - `"cannot use operator[] with string"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value - - @since version 1.0.0 - */ - reference operator[](const typename object_t::key_type& key) - { - // implicitly convert null value to an empty object - if (is_null()) - { - m_type = value_t::object; - m_value.object = create<object_t>(); - assert_invariant(); - } - - // operator[] only works for objects - if (is_object()) - { - return m_value.object->operator[](key); - } - - JSON_THROW(std::domain_error("cannot use operator[] with " + type_name())); - } - - /*! - @brief read-only access specified object element - - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. - - @warning If the element with key @a key does not exist, the behavior is - undefined. - - @param[in] key key of the element to access - - @return const reference to the element at key @a key - - @pre The element with key @a key must exist. **This precondition is - enforced with an assertion.** - - @throw std::domain_error if JSON is not an object; example: `"cannot use - operator[] with null"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value - - @since version 1.0.0 - */ - const_reference operator[](const typename object_t::key_type& key) const - { - // const operator[] only works for objects - if (is_object()) - { - assert(m_value.object->find(key) != m_value.object->end()); - return m_value.object->find(key)->second; - } - - JSON_THROW(std::domain_error("cannot use operator[] with " + type_name())); - } - - /*! - @brief access specified object element - - Returns a reference to the element at with specified key @a key. - - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. - - @param[in] key key of the element to access - - @return reference to the element at key @a key - - @throw std::domain_error if JSON is not an object or null; example: - `"cannot use operator[] with string"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value - - @since version 1.0.0 - */ - template<typename T, std::size_t n> - reference operator[](T * (&key)[n]) - { - return operator[](static_cast<const T>(key)); - } - - /*! - @brief read-only access specified object element - - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. - - @warning If the element with key @a key does not exist, the behavior is - undefined. - - @note This function is required for compatibility reasons with Clang. - - @param[in] key key of the element to access - - @return const reference to the element at key @a key - - @throw std::domain_error if JSON is not an object; example: `"cannot use - operator[] with null"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value - - @since version 1.0.0 - */ - template<typename T, std::size_t n> - const_reference operator[](T * (&key)[n]) const - { - return operator[](static_cast<const T>(key)); - } - - /*! - @brief access specified object element - - Returns a reference to the element at with specified key @a key. - - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. - - @param[in] key key of the element to access - - @return reference to the element at key @a key - - @throw std::domain_error if JSON is not an object or null; example: - `"cannot use operator[] with string"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value - - @since version 1.1.0 - */ - template<typename T> - reference operator[](T* key) - { - // implicitly convert null to object - if (is_null()) - { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); - } - - // at only works for objects - if (is_object()) - { - return m_value.object->operator[](key); - } - - JSON_THROW(std::domain_error("cannot use operator[] with " + type_name())); - } - - /*! - @brief read-only access specified object element - - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. - - @warning If the element with key @a key does not exist, the behavior is - undefined. - - @param[in] key key of the element to access - - @return const reference to the element at key @a key - - @pre The element with key @a key must exist. **This precondition is - enforced with an assertion.** - - @throw std::domain_error if JSON is not an object; example: `"cannot use - operator[] with null"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value - - @since version 1.1.0 - */ - template<typename T> - const_reference operator[](T* key) const - { - // at only works for objects - if (is_object()) - { - assert(m_value.object->find(key) != m_value.object->end()); - return m_value.object->find(key)->second; - } - - JSON_THROW(std::domain_error("cannot use operator[] with " + type_name())); - } - - /*! - @brief access specified object element with default value - - Returns either a copy of an object's element at the specified key @a key - or a given default value if no element with key @a key exists. - - The function is basically equivalent to executing - @code {.cpp} - try { - return at(key); - } catch(std::out_of_range) { - return default_value; - } - @endcode - - @note Unlike @ref at(const typename object_t::key_type&), this function - does not throw if the given key @a key was not found. - - @note Unlike @ref operator[](const typename object_t::key_type& key), this - function does not implicitly add an element to the position defined by @a - key. This function is furthermore also applicable to const objects. - - @param[in] key key of the element to access - @param[in] default_value the value to return if @a key is not found - - @tparam ValueType type compatible to JSON values, for instance `int` for - JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for - JSON arrays. Note the type of the expected value at @a key and the default - value @a default_value must be compatible. - - @return copy of the element at key @a key or @a default_value if @a key - is not found - - @throw std::domain_error if JSON is not an object; example: `"cannot use - value() with null"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be queried - with a default value.,basic_json__value} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - - @since version 1.0.0 - */ - template<class ValueType, typename std::enable_if< - std::is_convertible<basic_json_t, ValueType>::value, int>::type = 0> - ValueType value(const typename object_t::key_type& key, ValueType default_value) const - { - // at only works for objects - if (is_object()) - { - // if key is found, return value and given default value otherwise - const auto it = find(key); - if (it != end()) - { - return *it; - } - - return default_value; - } - else - { - JSON_THROW(std::domain_error("cannot use value() with " + type_name())); - } - } - - /*! - @brief overload for a default value of type const char* - @copydoc basic_json::value(const typename object_t::key_type&, ValueType) const - */ - string_t value(const typename object_t::key_type& key, const char* default_value) const - { - return value(key, string_t(default_value)); - } - - /*! - @brief access specified object element via JSON Pointer with default value - - Returns either a copy of an object's element at the specified key @a key - or a given default value if no element with key @a key exists. - - The function is basically equivalent to executing - @code {.cpp} - try { - return at(ptr); - } catch(std::out_of_range) { - return default_value; - } - @endcode - - @note Unlike @ref at(const json_pointer&), this function does not throw - if the given key @a key was not found. - - @param[in] ptr a JSON pointer to the element to access - @param[in] default_value the value to return if @a ptr found no value - - @tparam ValueType type compatible to JSON values, for instance `int` for - JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for - JSON arrays. Note the type of the expected value at @a key and the default - value @a default_value must be compatible. - - @return copy of the element at key @a key or @a default_value if @a key - is not found - - @throw std::domain_error if JSON is not an object; example: `"cannot use - value() with null"` - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be queried - with a default value.,basic_json__value_ptr} - - @sa @ref operator[](const json_pointer&) for unchecked access by reference - - @since version 2.0.2 - */ - template<class ValueType, typename std::enable_if< - std::is_convertible<basic_json_t, ValueType>::value, int>::type = 0> - ValueType value(const json_pointer& ptr, ValueType default_value) const - { - // at only works for objects - if (is_object()) - { - // if pointer resolves a value, return it or use default value - JSON_TRY - { - return ptr.get_checked(this); - } - JSON_CATCH (std::out_of_range&) - { - return default_value; - } - } - - JSON_THROW(std::domain_error("cannot use value() with " + type_name())); - } - - /*! - @brief overload for a default value of type const char* - @copydoc basic_json::value(const json_pointer&, ValueType) const - */ - string_t value(const json_pointer& ptr, const char* default_value) const - { - return value(ptr, string_t(default_value)); - } - - /*! - @brief access the first element - - Returns a reference to the first element in the container. For a JSON - container `c`, the expression `c.front()` is equivalent to `*c.begin()`. - - @return In case of a structured type (array or object), a reference to the - first element is returned. In case of number, string, or boolean values, a - reference to the value is returned. - - @complexity Constant. - - @pre The JSON value must not be `null` (would throw `std::out_of_range`) - or an empty array or object (undefined behavior, **guarded by - assertions**). - @post The JSON value remains unchanged. - - @throw std::out_of_range when called on `null` value - - @liveexample{The following code shows an example for `front()`.,front} - - @sa @ref back() -- access the last element - - @since version 1.0.0 - */ - reference front() - { - return *begin(); - } - - /*! - @copydoc basic_json::front() - */ - const_reference front() const - { - return *cbegin(); - } - - /*! - @brief access the last element - - Returns a reference to the last element in the container. For a JSON - container `c`, the expression `c.back()` is equivalent to - @code {.cpp} - auto tmp = c.end(); - --tmp; - return *tmp; - @endcode - - @return In case of a structured type (array or object), a reference to the - last element is returned. In case of number, string, or boolean values, a - reference to the value is returned. - - @complexity Constant. - - @pre The JSON value must not be `null` (would throw `std::out_of_range`) - or an empty array or object (undefined behavior, **guarded by - assertions**). - @post The JSON value remains unchanged. - - @throw std::out_of_range when called on `null` value. - - @liveexample{The following code shows an example for `back()`.,back} - - @sa @ref front() -- access the first element - - @since version 1.0.0 - */ - reference back() - { - auto tmp = end(); - --tmp; - return *tmp; - } - - /*! - @copydoc basic_json::back() - */ - const_reference back() const - { - auto tmp = cend(); - --tmp; - return *tmp; - } - - /*! - @brief remove element given an iterator - - Removes the element specified by iterator @a pos. The iterator @a pos must - be valid and dereferenceable. Thus the `end()` iterator (which is valid, - but is not dereferenceable) cannot be used as a value for @a pos. - - If called on a primitive type other than `null`, the resulting JSON value - will be `null`. - - @param[in] pos iterator to the element to remove - @return Iterator following the last removed element. If the iterator @a - pos refers to the last element, the `end()` iterator is returned. - - @tparam IteratorType an @ref iterator or @ref const_iterator - - @post Invalidates iterators and references at or after the point of the - erase, including the `end()` iterator. - - @throw std::domain_error if called on a `null` value; example: `"cannot - use erase() with null"` - @throw std::domain_error if called on an iterator which does not belong to - the current JSON value; example: `"iterator does not fit current value"` - @throw std::out_of_range if called on a primitive type with invalid - iterator (i.e., any iterator which is not `begin()`); example: `"iterator - out of range"` - - @complexity The complexity depends on the type: - - objects: amortized constant - - arrays: linear in distance between @a pos and the end of the container - - strings: linear in the length of the string - - other types: constant - - @liveexample{The example shows the result of `erase()` for different JSON - types.,erase__IteratorType} - - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key - @sa @ref erase(const size_type) -- removes the element from an array at - the given index - - @since version 1.0.0 - */ - template<class IteratorType, typename std::enable_if< - std::is_same<IteratorType, typename basic_json_t::iterator>::value or - std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int>::type - = 0> - IteratorType erase(IteratorType pos) - { - // make sure iterator fits the current value - if (this != pos.m_object) - { - JSON_THROW(std::domain_error("iterator does not fit current value")); - } - - IteratorType result = end(); - - switch (m_type) - { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: - { - if (not pos.m_it.primitive_iterator.is_begin()) - { - JSON_THROW(std::out_of_range("iterator out of range")); - } - - if (is_string()) - { - AllocatorType<string_t> alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - m_value.string = nullptr; - } - - m_type = value_t::null; - assert_invariant(); - break; - } - - case value_t::object: - { - result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator); - break; - } - - case value_t::array: - { - result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator); - break; - } - - default: - { - JSON_THROW(std::domain_error("cannot use erase() with " + type_name())); - } - } - - return result; - } - - /*! - @brief remove elements given an iterator range - - Removes the element specified by the range `[first; last)`. The iterator - @a first does not need to be dereferenceable if `first == last`: erasing - an empty range is a no-op. - - If called on a primitive type other than `null`, the resulting JSON value - will be `null`. - - @param[in] first iterator to the beginning of the range to remove - @param[in] last iterator past the end of the range to remove - @return Iterator following the last removed element. If the iterator @a - second refers to the last element, the `end()` iterator is returned. - - @tparam IteratorType an @ref iterator or @ref const_iterator - - @post Invalidates iterators and references at or after the point of the - erase, including the `end()` iterator. - - @throw std::domain_error if called on a `null` value; example: `"cannot - use erase() with null"` - @throw std::domain_error if called on iterators which does not belong to - the current JSON value; example: `"iterators do not fit current value"` - @throw std::out_of_range if called on a primitive type with invalid - iterators (i.e., if `first != begin()` and `last != end()`); example: - `"iterators out of range"` - - @complexity The complexity depends on the type: - - objects: `log(size()) + std::distance(first, last)` - - arrays: linear in the distance between @a first and @a last, plus linear - in the distance between @a last and end of the container - - strings: linear in the length of the string - - other types: constant - - @liveexample{The example shows the result of `erase()` for different JSON - types.,erase__IteratorType_IteratorType} - - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key - @sa @ref erase(const size_type) -- removes the element from an array at - the given index - - @since version 1.0.0 - */ - template<class IteratorType, typename std::enable_if< - std::is_same<IteratorType, typename basic_json_t::iterator>::value or - std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int>::type - = 0> - IteratorType erase(IteratorType first, IteratorType last) - { - // make sure iterator fits the current value - if (this != first.m_object or this != last.m_object) - { - JSON_THROW(std::domain_error("iterators do not fit current value")); - } - - IteratorType result = end(); - - switch (m_type) - { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: - { - if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end()) - { - JSON_THROW(std::out_of_range("iterators out of range")); - } - - if (is_string()) - { - AllocatorType<string_t> alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - m_value.string = nullptr; - } - - m_type = value_t::null; - assert_invariant(); - break; - } - - case value_t::object: - { - result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator, - last.m_it.object_iterator); - break; - } - - case value_t::array: - { - result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator, - last.m_it.array_iterator); - break; - } - - default: - { - JSON_THROW(std::domain_error("cannot use erase() with " + type_name())); - } - } - - return result; - } - - /*! - @brief remove element from a JSON object given a key - - Removes elements from a JSON object with the key value @a key. - - @param[in] key value of the elements to remove - - @return Number of elements removed. If @a ObjectType is the default - `std::map` type, the return value will always be `0` (@a key was not - found) or `1` (@a key was found). - - @post References and iterators to the erased elements are invalidated. - Other references and iterators are not affected. - - @throw std::domain_error when called on a type other than JSON object; - example: `"cannot use erase() with null"` - - @complexity `log(size()) + count(key)` - - @liveexample{The example shows the effect of `erase()`.,erase__key_type} - - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const size_type) -- removes the element from an array at - the given index - - @since version 1.0.0 - */ - size_type erase(const typename object_t::key_type& key) - { - // this erase only works for objects - if (is_object()) - { - return m_value.object->erase(key); - } - - JSON_THROW(std::domain_error("cannot use erase() with " + type_name())); - } - - /*! - @brief remove element from a JSON array given an index - - Removes element from a JSON array at the index @a idx. - - @param[in] idx index of the element to remove - - @throw std::domain_error when called on a type other than JSON array; - example: `"cannot use erase() with null"` - @throw std::out_of_range when `idx >= size()`; example: `"array index 17 - is out of range"` - - @complexity Linear in distance between @a idx and the end of the container. - - @liveexample{The example shows the effect of `erase()`.,erase__size_type} - - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key - - @since version 1.0.0 - */ - void erase(const size_type idx) - { - // this erase only works for arrays - if (is_array()) - { - if (idx >= size()) - { - JSON_THROW(std::out_of_range("array index " + std::to_string(idx) + " is out of range")); - } - - m_value.array->erase(m_value.array->begin() + static_cast<difference_type>(idx)); - } - else - { - JSON_THROW(std::domain_error("cannot use erase() with " + type_name())); - } - } - - /// @} - - - //////////// - // lookup // - //////////// - - /// @name lookup - /// @{ - - /*! - @brief find an element in a JSON object - - Finds an element in a JSON object with key equivalent to @a key. If the - element is not found or the JSON value is not an object, end() is - returned. - - @note This method always returns @ref end() when executed on a JSON type - that is not an object. - - @param[in] key key value of the element to search for - - @return Iterator to an element with key equivalent to @a key. If no such - element is found or the JSON value is not an object, past-the-end (see - @ref end()) iterator is returned. - - @complexity Logarithmic in the size of the JSON object. - - @liveexample{The example shows how `find()` is used.,find__key_type} - - @since version 1.0.0 - */ - iterator find(typename object_t::key_type key) - { - auto result = end(); - - if (is_object()) - { - result.m_it.object_iterator = m_value.object->find(key); - } - - return result; - } - - /*! - @brief find an element in a JSON object - @copydoc find(typename object_t::key_type) - */ - const_iterator find(typename object_t::key_type key) const - { - auto result = cend(); - - if (is_object()) - { - result.m_it.object_iterator = m_value.object->find(key); - } - - return result; - } - - /*! - @brief returns the number of occurrences of a key in a JSON object - - Returns the number of elements with key @a key. If ObjectType is the - default `std::map` type, the return value will always be `0` (@a key was - not found) or `1` (@a key was found). - - @note This method always returns `0` when executed on a JSON type that is - not an object. - - @param[in] key key value of the element to count - - @return Number of elements with key @a key. If the JSON value is not an - object, the return value will be `0`. - - @complexity Logarithmic in the size of the JSON object. - - @liveexample{The example shows how `count()` is used.,count} - - @since version 1.0.0 - */ - size_type count(typename object_t::key_type key) const - { - // return 0 for all nonobject types - return is_object() ? m_value.object->count(key) : 0; - } - - /// @} - - - /////////////// - // iterators // - /////////////// - - /// @name iterators - /// @{ - - /*! - @brief returns an iterator to the first element - - Returns an iterator to the first element. - - @image html range-begin-end.svg "Illustration from cppreference.com" - - @return iterator to the first element - - @complexity Constant. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - @liveexample{The following code shows an example for `begin()`.,begin} - - @sa @ref cbegin() -- returns a const iterator to the beginning - @sa @ref end() -- returns an iterator to the end - @sa @ref cend() -- returns a const iterator to the end - - @since version 1.0.0 - */ - iterator begin() noexcept - { - iterator result(this); - result.set_begin(); - return result; - } - - /*! - @copydoc basic_json::cbegin() - */ - const_iterator begin() const noexcept - { - return cbegin(); - } - - /*! - @brief returns a const iterator to the first element - - Returns a const iterator to the first element. - - @image html range-begin-end.svg "Illustration from cppreference.com" - - @return const iterator to the first element - - @complexity Constant. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast<const basic_json&>(*this).begin()`. - - @liveexample{The following code shows an example for `cbegin()`.,cbegin} - - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref end() -- returns an iterator to the end - @sa @ref cend() -- returns a const iterator to the end - - @since version 1.0.0 - */ - const_iterator cbegin() const noexcept - { - const_iterator result(this); - result.set_begin(); - return result; - } - - /*! - @brief returns an iterator to one past the last element - - Returns an iterator to one past the last element. - - @image html range-begin-end.svg "Illustration from cppreference.com" - - @return iterator one past the last element - - @complexity Constant. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - @liveexample{The following code shows an example for `end()`.,end} - - @sa @ref cend() -- returns a const iterator to the end - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref cbegin() -- returns a const iterator to the beginning - - @since version 1.0.0 - */ - iterator end() noexcept - { - iterator result(this); - result.set_end(); - return result; - } - - /*! - @copydoc basic_json::cend() - */ - const_iterator end() const noexcept - { - return cend(); - } - - /*! - @brief returns a const iterator to one past the last element - - Returns a const iterator to one past the last element. - - @image html range-begin-end.svg "Illustration from cppreference.com" - - @return const iterator one past the last element - - @complexity Constant. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast<const basic_json&>(*this).end()`. - - @liveexample{The following code shows an example for `cend()`.,cend} - - @sa @ref end() -- returns an iterator to the end - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref cbegin() -- returns a const iterator to the beginning - - @since version 1.0.0 - */ - const_iterator cend() const noexcept - { - const_iterator result(this); - result.set_end(); - return result; - } - - /*! - @brief returns an iterator to the reverse-beginning - - Returns an iterator to the reverse-beginning; that is, the last element. - - @image html range-rbegin-rend.svg "Illustration from cppreference.com" - - @complexity Constant. - - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `reverse_iterator(end())`. - - @liveexample{The following code shows an example for `rbegin()`.,rbegin} - - @sa @ref crbegin() -- returns a const reverse iterator to the beginning - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref crend() -- returns a const reverse iterator to the end - - @since version 1.0.0 - */ - reverse_iterator rbegin() noexcept - { - return reverse_iterator(end()); - } - - /*! - @copydoc basic_json::crbegin() - */ - const_reverse_iterator rbegin() const noexcept - { - return crbegin(); - } - - /*! - @brief returns an iterator to the reverse-end - - Returns an iterator to the reverse-end; that is, one before the first - element. - - @image html range-rbegin-rend.svg "Illustration from cppreference.com" - - @complexity Constant. - - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `reverse_iterator(begin())`. - - @liveexample{The following code shows an example for `rend()`.,rend} - - @sa @ref crend() -- returns a const reverse iterator to the end - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref crbegin() -- returns a const reverse iterator to the beginning - - @since version 1.0.0 - */ - reverse_iterator rend() noexcept - { - return reverse_iterator(begin()); - } - - /*! - @copydoc basic_json::crend() - */ - const_reverse_iterator rend() const noexcept - { - return crend(); - } - - /*! - @brief returns a const reverse iterator to the last element - - Returns a const iterator to the reverse-beginning; that is, the last - element. - - @image html range-rbegin-rend.svg "Illustration from cppreference.com" - - @complexity Constant. - - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast<const basic_json&>(*this).rbegin()`. - - @liveexample{The following code shows an example for `crbegin()`.,crbegin} - - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref crend() -- returns a const reverse iterator to the end - - @since version 1.0.0 - */ - const_reverse_iterator crbegin() const noexcept - { - return const_reverse_iterator(cend()); - } - - /*! - @brief returns a const reverse iterator to one before the first - - Returns a const reverse iterator to the reverse-end; that is, one before - the first element. - - @image html range-rbegin-rend.svg "Illustration from cppreference.com" - - @complexity Constant. - - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast<const basic_json&>(*this).rend()`. - - @liveexample{The following code shows an example for `crend()`.,crend} - - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref crbegin() -- returns a const reverse iterator to the beginning - - @since version 1.0.0 - */ - const_reverse_iterator crend() const noexcept - { - return const_reverse_iterator(cbegin()); - } - - private: - // forward declaration - template<typename IteratorType> class iteration_proxy; - - public: - /*! - @brief wrapper to access iterator member functions in range-based for - - This function allows to access @ref iterator::key() and @ref - iterator::value() during range-based for loops. In these loops, a - reference to the JSON values is returned, so there is no access to the - underlying iterator. - - @note The name of this function is not yet final and may change in the - future. - */ - static iteration_proxy<iterator> iterator_wrapper(reference cont) - { - return iteration_proxy<iterator>(cont); - } - - /*! - @copydoc iterator_wrapper(reference) - */ - static iteration_proxy<const_iterator> iterator_wrapper(const_reference cont) - { - return iteration_proxy<const_iterator>(cont); - } - - /// @} - - - ////////////// - // capacity // - ////////////// - - /// @name capacity - /// @{ - - /*! - @brief checks whether the container is empty - - Checks if a JSON value has no elements. - - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `true` - boolean | `false` - string | `false` - number | `false` - object | result of function `object_t::empty()` - array | result of function `array_t::empty()` - - @note This function does not return whether a string stored as JSON value - is empty - it returns whether the JSON container itself is empty which is - false in the case of a string. - - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their `empty()` functions have constant - complexity. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `begin() == end()`. - - @liveexample{The following code uses `empty()` to check if a JSON - object contains any elements.,empty} - - @sa @ref size() -- returns the number of elements - - @since version 1.0.0 - */ - bool empty() const noexcept - { - switch (m_type) - { - case value_t::null: - { - // null values are empty - return true; - } - - case value_t::array: - { - // delegate call to array_t::empty() - return m_value.array->empty(); - } - - case value_t::object: - { - // delegate call to object_t::empty() - return m_value.object->empty(); - } - - default: - { - // all other types are nonempty - return false; - } - } - } - - /*! - @brief returns the number of elements - - Returns the number of elements in a JSON value. - - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `0` - boolean | `1` - string | `1` - number | `1` - object | result of function object_t::size() - array | result of function array_t::size() - - @note This function does not return the length of a string stored as JSON - value - it returns the number of elements in the JSON value which is 1 in - the case of a string. - - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their size() functions have constant - complexity. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `std::distance(begin(), end())`. - - @liveexample{The following code calls `size()` on the different value - types.,size} - - @sa @ref empty() -- checks whether the container is empty - @sa @ref max_size() -- returns the maximal number of elements - - @since version 1.0.0 - */ - size_type size() const noexcept - { - switch (m_type) - { - case value_t::null: - { - // null values are empty - return 0; - } - - case value_t::array: - { - // delegate call to array_t::size() - return m_value.array->size(); - } - - case value_t::object: - { - // delegate call to object_t::size() - return m_value.object->size(); - } - - default: - { - // all other types have size 1 - return 1; - } - } - } - - /*! - @brief returns the maximum possible number of elements - - Returns the maximum number of elements a JSON value is able to hold due to - system or library implementation limitations, i.e. `std::distance(begin(), - end())` for the JSON value. - - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `0` (same as `size()`) - boolean | `1` (same as `size()`) - string | `1` (same as `size()`) - number | `1` (same as `size()`) - object | result of function `object_t::max_size()` - array | result of function `array_t::max_size()` - - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their `max_size()` functions have constant - complexity. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of returning `b.size()` where `b` is the largest - possible JSON value. - - @liveexample{The following code calls `max_size()` on the different value - types. Note the output is implementation specific.,max_size} - - @sa @ref size() -- returns the number of elements - - @since version 1.0.0 - */ - size_type max_size() const noexcept - { - switch (m_type) - { - case value_t::array: - { - // delegate call to array_t::max_size() - return m_value.array->max_size(); - } - - case value_t::object: - { - // delegate call to object_t::max_size() - return m_value.object->max_size(); - } - - default: - { - // all other types have max_size() == size() - return size(); - } - } - } - - /// @} - - - /////////////// - // modifiers // - /////////////// - - /// @name modifiers - /// @{ - - /*! - @brief clears the contents - - Clears the content of a JSON value and resets it to the default value as - if @ref basic_json(value_t) would have been called: - - Value type | initial value - ----------- | ------------- - null | `null` - boolean | `false` - string | `""` - number | `0` - object | `{}` - array | `[]` - - @complexity Linear in the size of the JSON value. - - @liveexample{The example below shows the effect of `clear()` to different - JSON types.,clear} - - @since version 1.0.0 - */ - void clear() noexcept - { - switch (m_type) - { - case value_t::number_integer: - { - m_value.number_integer = 0; - break; - } - - case value_t::number_unsigned: - { - m_value.number_unsigned = 0; - break; - } - - case value_t::number_float: - { - m_value.number_float = 0.0; - break; - } - - case value_t::boolean: - { - m_value.boolean = false; - break; - } - - case value_t::string: - { - m_value.string->clear(); - break; - } - - case value_t::array: - { - m_value.array->clear(); - break; - } - - case value_t::object: - { - m_value.object->clear(); - break; - } - - default: - { - break; - } - } - } - - /*! - @brief add an object to an array - - Appends the given element @a val to the end of the JSON value. If the - function is called on a JSON null value, an empty array is created before - appending @a val. - - @param[in] val the value to add to the JSON array - - @throw std::domain_error when called on a type other than JSON array or - null; example: `"cannot use push_back() with number"` - - @complexity Amortized constant. - - @liveexample{The example shows how `push_back()` and `+=` can be used to - add elements to a JSON array. Note how the `null` value was silently - converted to a JSON array.,push_back} - - @since version 1.0.0 - */ - void push_back(basic_json&& val) - { - // push_back only works for null objects or arrays - if (not(is_null() or is_array())) - { - JSON_THROW(std::domain_error("cannot use push_back() with " + type_name())); - } - - // transform null object into an array - if (is_null()) - { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } - - // add element to array (move semantics) - m_value.array->push_back(std::move(val)); - // invalidate object - val.m_type = value_t::null; - } - - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - reference operator+=(basic_json&& val) - { - push_back(std::move(val)); - return *this; - } - - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - void push_back(const basic_json& val) - { - // push_back only works for null objects or arrays - if (not(is_null() or is_array())) - { - JSON_THROW(std::domain_error("cannot use push_back() with " + type_name())); - } - - // transform null object into an array - if (is_null()) - { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } - - // add element to array - m_value.array->push_back(val); - } - - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - reference operator+=(const basic_json& val) - { - push_back(val); - return *this; - } - - /*! - @brief add an object to an object - - Inserts the given element @a val to the JSON object. If the function is - called on a JSON null value, an empty object is created before inserting - @a val. - - @param[in] val the value to add to the JSON object - - @throw std::domain_error when called on a type other than JSON object or - null; example: `"cannot use push_back() with number"` - - @complexity Logarithmic in the size of the container, O(log(`size()`)). - - @liveexample{The example shows how `push_back()` and `+=` can be used to - add elements to a JSON object. Note how the `null` value was silently - converted to a JSON object.,push_back__object_t__value} - - @since version 1.0.0 - */ - void push_back(const typename object_t::value_type& val) - { - // push_back only works for null objects or objects - if (not(is_null() or is_object())) - { - JSON_THROW(std::domain_error("cannot use push_back() with " + type_name())); - } - - // transform null object into an object - if (is_null()) - { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); - } - - // add element to array - m_value.object->insert(val); - } - - /*! - @brief add an object to an object - @copydoc push_back(const typename object_t::value_type&) - */ - reference operator+=(const typename object_t::value_type& val) - { - push_back(val); - return *this; - } - - /*! - @brief add an object to an object - - This function allows to use `push_back` with an initializer list. In case - - 1. the current value is an object, - 2. the initializer list @a init contains only two elements, and - 3. the first element of @a init is a string, - - @a init is converted into an object element and added using - @ref push_back(const typename object_t::value_type&). Otherwise, @a init - is converted to a JSON value and added using @ref push_back(basic_json&&). - - @param init an initializer list - - @complexity Linear in the size of the initializer list @a init. - - @note This function is required to resolve an ambiguous overload error, - because pairs like `{"key", "value"}` can be both interpreted as - `object_t::value_type` or `std::initializer_list<basic_json>`, see - https://github.com/nlohmann/json/issues/235 for more information. - - @liveexample{The example shows how initializer lists are treated as - objects when possible.,push_back__initializer_list} - */ - void push_back(std::initializer_list<basic_json> init) - { - if (is_object() and init.size() == 2 and init.begin()->is_string()) - { - const string_t key = *init.begin(); - push_back(typename object_t::value_type(key, *(init.begin() + 1))); - } - else - { - push_back(basic_json(init)); - } - } - - /*! - @brief add an object to an object - @copydoc push_back(std::initializer_list<basic_json>) - */ - reference operator+=(std::initializer_list<basic_json> init) - { - push_back(init); - return *this; - } - - /*! - @brief add an object to an array - - Creates a JSON value from the passed parameters @a args to the end of the - JSON value. If the function is called on a JSON null value, an empty array - is created before appending the value created from @a args. - - @param[in] args arguments to forward to a constructor of @ref basic_json - @tparam Args compatible types to create a @ref basic_json object - - @throw std::domain_error when called on a type other than JSON array or - null; example: `"cannot use emplace_back() with number"` - - @complexity Amortized constant. - - @liveexample{The example shows how `push_back()` can be used to add - elements to a JSON array. Note how the `null` value was silently converted - to a JSON array.,emplace_back} - - @since version 2.0.8 - */ - template<class... Args> - void emplace_back(Args&& ... args) - { - // emplace_back only works for null objects or arrays - if (not(is_null() or is_array())) - { - JSON_THROW(std::domain_error("cannot use emplace_back() with " + type_name())); - } - - // transform null object into an array - if (is_null()) - { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } - - // add element to array (perfect forwarding) - m_value.array->emplace_back(std::forward<Args>(args)...); - } - - /*! - @brief add an object to an object if key does not exist - - Inserts a new element into a JSON object constructed in-place with the - given @a args if there is no element with the key in the container. If the - function is called on a JSON null value, an empty object is created before - appending the value created from @a args. - - @param[in] args arguments to forward to a constructor of @ref basic_json - @tparam Args compatible types to create a @ref basic_json object - - @return a pair consisting of an iterator to the inserted element, or the - already-existing element if no insertion happened, and a bool - denoting whether the insertion took place. - - @throw std::domain_error when called on a type other than JSON object or - null; example: `"cannot use emplace() with number"` - - @complexity Logarithmic in the size of the container, O(log(`size()`)). - - @liveexample{The example shows how `emplace()` can be used to add elements - to a JSON object. Note how the `null` value was silently converted to a - JSON object. Further note how no value is added if there was already one - value stored with the same key.,emplace} - - @since version 2.0.8 - */ - template<class... Args> - std::pair<iterator, bool> emplace(Args&& ... args) - { - // emplace only works for null objects or arrays - if (not(is_null() or is_object())) - { - JSON_THROW(std::domain_error("cannot use emplace() with " + type_name())); - } - - // transform null object into an object - if (is_null()) - { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); - } - - // add element to array (perfect forwarding) - auto res = m_value.object->emplace(std::forward<Args>(args)...); - // create result iterator and set iterator to the result of emplace - auto it = begin(); - it.m_it.object_iterator = res.first; - - // return pair of iterator and boolean - return {it, res.second}; - } - - /*! - @brief inserts element - - Inserts element @a val before iterator @a pos. - - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] val element to insert - @return iterator pointing to the inserted @a val. - - @throw std::domain_error if called on JSON values other than arrays; - example: `"cannot use insert() with string"` - @throw std::domain_error if @a pos is not an iterator of *this; example: - `"iterator does not fit current value"` - - @complexity Constant plus linear in the distance between @a pos and end of - the container. - - @liveexample{The example shows how `insert()` is used.,insert} - - @since version 1.0.0 - */ - iterator insert(const_iterator pos, const basic_json& val) - { - // insert only works for arrays - if (is_array()) - { - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(std::domain_error("iterator does not fit current value")); - } - - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, val); - return result; - } - - JSON_THROW(std::domain_error("cannot use insert() with " + type_name())); - } - - /*! - @brief inserts element - @copydoc insert(const_iterator, const basic_json&) - */ - iterator insert(const_iterator pos, basic_json&& val) - { - return insert(pos, val); - } - - /*! - @brief inserts elements - - Inserts @a cnt copies of @a val before iterator @a pos. - - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] cnt number of copies of @a val to insert - @param[in] val element to insert - @return iterator pointing to the first element inserted, or @a pos if - `cnt==0` - - @throw std::domain_error if called on JSON values other than arrays; - example: `"cannot use insert() with string"` - @throw std::domain_error if @a pos is not an iterator of *this; example: - `"iterator does not fit current value"` - - @complexity Linear in @a cnt plus linear in the distance between @a pos - and end of the container. - - @liveexample{The example shows how `insert()` is used.,insert__count} - - @since version 1.0.0 - */ - iterator insert(const_iterator pos, size_type cnt, const basic_json& val) - { - // insert only works for arrays - if (is_array()) - { - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(std::domain_error("iterator does not fit current value")); - } - - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val); - return result; - } - - JSON_THROW(std::domain_error("cannot use insert() with " + type_name())); - } - - /*! - @brief inserts elements - - Inserts elements from range `[first, last)` before iterator @a pos. - - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] first begin of the range of elements to insert - @param[in] last end of the range of elements to insert - - @throw std::domain_error if called on JSON values other than arrays; - example: `"cannot use insert() with string"` - @throw std::domain_error if @a pos is not an iterator of *this; example: - `"iterator does not fit current value"` - @throw std::domain_error if @a first and @a last do not belong to the same - JSON value; example: `"iterators do not fit"` - @throw std::domain_error if @a first or @a last are iterators into - container for which insert is called; example: `"passed iterators may not - belong to container"` - - @return iterator pointing to the first element inserted, or @a pos if - `first==last` - - @complexity Linear in `std::distance(first, last)` plus linear in the - distance between @a pos and end of the container. - - @liveexample{The example shows how `insert()` is used.,insert__range} - - @since version 1.0.0 - */ - iterator insert(const_iterator pos, const_iterator first, const_iterator last) - { - // insert only works for arrays - if (not is_array()) - { - JSON_THROW(std::domain_error("cannot use insert() with " + type_name())); - } - - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(std::domain_error("iterator does not fit current value")); - } - - // check if range iterators belong to the same JSON object - if (first.m_object != last.m_object) - { - JSON_THROW(std::domain_error("iterators do not fit")); - } - - if (first.m_object == this or last.m_object == this) - { - JSON_THROW(std::domain_error("passed iterators may not belong to container")); - } - - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert( - pos.m_it.array_iterator, - first.m_it.array_iterator, - last.m_it.array_iterator); - return result; - } - - /*! - @brief inserts elements - - Inserts elements from initializer list @a ilist before iterator @a pos. - - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] ilist initializer list to insert the values from - - @throw std::domain_error if called on JSON values other than arrays; - example: `"cannot use insert() with string"` - @throw std::domain_error if @a pos is not an iterator of *this; example: - `"iterator does not fit current value"` - - @return iterator pointing to the first element inserted, or @a pos if - `ilist` is empty - - @complexity Linear in `ilist.size()` plus linear in the distance between - @a pos and end of the container. - - @liveexample{The example shows how `insert()` is used.,insert__ilist} - - @since version 1.0.0 - */ - iterator insert(const_iterator pos, std::initializer_list<basic_json> ilist) - { - // insert only works for arrays - if (not is_array()) - { - JSON_THROW(std::domain_error("cannot use insert() with " + type_name())); - } - - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(std::domain_error("iterator does not fit current value")); - } - - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist); - return result; - } - - /*! - @brief exchanges the values - - Exchanges the contents of the JSON value with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. - - @param[in,out] other JSON value to exchange the contents with - - @complexity Constant. - - @liveexample{The example below shows how JSON values can be swapped with - `swap()`.,swap__reference} - - @since version 1.0.0 - */ - void swap(reference other) noexcept ( - std::is_nothrow_move_constructible<value_t>::value and - std::is_nothrow_move_assignable<value_t>::value and - std::is_nothrow_move_constructible<json_value>::value and - std::is_nothrow_move_assignable<json_value>::value - ) - { - std::swap(m_type, other.m_type); - std::swap(m_value, other.m_value); - assert_invariant(); - } - - /*! - @brief exchanges the values - - Exchanges the contents of a JSON array with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. - - @param[in,out] other array to exchange the contents with - - @throw std::domain_error when JSON value is not an array; example: - `"cannot use swap() with string"` - - @complexity Constant. - - @liveexample{The example below shows how arrays can be swapped with - `swap()`.,swap__array_t} - - @since version 1.0.0 - */ - void swap(array_t& other) - { - // swap only works for arrays - if (is_array()) - { - std::swap(*(m_value.array), other); - } - else - { - JSON_THROW(std::domain_error("cannot use swap() with " + type_name())); - } - } - - /*! - @brief exchanges the values - - Exchanges the contents of a JSON object with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. - - @param[in,out] other object to exchange the contents with - - @throw std::domain_error when JSON value is not an object; example: - `"cannot use swap() with string"` - - @complexity Constant. - - @liveexample{The example below shows how objects can be swapped with - `swap()`.,swap__object_t} - - @since version 1.0.0 - */ - void swap(object_t& other) - { - // swap only works for objects - if (is_object()) - { - std::swap(*(m_value.object), other); - } - else - { - JSON_THROW(std::domain_error("cannot use swap() with " + type_name())); - } - } - - /*! - @brief exchanges the values - - Exchanges the contents of a JSON string with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. - - @param[in,out] other string to exchange the contents with - - @throw std::domain_error when JSON value is not a string; example: `"cannot - use swap() with boolean"` - - @complexity Constant. - - @liveexample{The example below shows how strings can be swapped with - `swap()`.,swap__string_t} - - @since version 1.0.0 - */ - void swap(string_t& other) - { - // swap only works for strings - if (is_string()) - { - std::swap(*(m_value.string), other); - } - else - { - JSON_THROW(std::domain_error("cannot use swap() with " + type_name())); - } - } - - /// @} - - public: - ////////////////////////////////////////// - // lexicographical comparison operators // - ////////////////////////////////////////// - - /// @name lexicographical comparison operators - /// @{ - - /*! - @brief comparison: equal - - Compares two JSON values for equality according to the following rules: - - Two JSON values are equal if (1) they are from the same type and (2) - their stored values are the same. - - Integer and floating-point numbers are automatically converted before - comparison. Floating-point numbers are compared indirectly: two - floating-point numbers `f1` and `f2` are considered equal if neither - `f1 > f2` nor `f2 > f1` holds. - - Two JSON null values are equal. - - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether the values @a lhs and @a rhs are equal - - @complexity Linear. - - @liveexample{The example demonstrates comparing several JSON - types.,operator__equal} - - @since version 1.0.0 - */ - friend bool operator==(const_reference lhs, const_reference rhs) noexcept - { - const auto lhs_type = lhs.type(); - const auto rhs_type = rhs.type(); - - if (lhs_type == rhs_type) - { - switch (lhs_type) - { - case value_t::array: - { - return *lhs.m_value.array == *rhs.m_value.array; - } - case value_t::object: - { - return *lhs.m_value.object == *rhs.m_value.object; - } - case value_t::null: - { - return true; - } - case value_t::string: - { - return *lhs.m_value.string == *rhs.m_value.string; - } - case value_t::boolean: - { - return lhs.m_value.boolean == rhs.m_value.boolean; - } - case value_t::number_integer: - { - return lhs.m_value.number_integer == rhs.m_value.number_integer; - } - case value_t::number_unsigned: - { - return lhs.m_value.number_unsigned == rhs.m_value.number_unsigned; - } - case value_t::number_float: - { - return lhs.m_value.number_float == rhs.m_value.number_float; - } - default: - { - return false; - } - } - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) - { - return static_cast<number_float_t>(lhs.m_value.number_integer) == rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) - { - return lhs.m_value.number_float == static_cast<number_float_t>(rhs.m_value.number_integer); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) - { - return static_cast<number_float_t>(lhs.m_value.number_unsigned) == rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_float == static_cast<number_float_t>(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) - { - return static_cast<number_integer_t>(lhs.m_value.number_unsigned) == rhs.m_value.number_integer; - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_integer == static_cast<number_integer_t>(rhs.m_value.number_unsigned); - } - - return false; - } - - /*! - @brief comparison: equal - @copydoc operator==(const_reference, const_reference) - */ - template<typename ScalarType, typename std::enable_if< - std::is_scalar<ScalarType>::value, int>::type = 0> - friend bool operator==(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs == basic_json(rhs)); - } - - /*! - @brief comparison: equal - @copydoc operator==(const_reference, const_reference) - */ - template<typename ScalarType, typename std::enable_if< - std::is_scalar<ScalarType>::value, int>::type = 0> - friend bool operator==(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) == rhs); - } - - /*! - @brief comparison: not equal - - Compares two JSON values for inequality by calculating `not (lhs == rhs)`. - - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether the values @a lhs and @a rhs are not equal - - @complexity Linear. - - @liveexample{The example demonstrates comparing several JSON - types.,operator__notequal} - - @since version 1.0.0 - */ - friend bool operator!=(const_reference lhs, const_reference rhs) noexcept - { - return not (lhs == rhs); - } - - /*! - @brief comparison: not equal - @copydoc operator!=(const_reference, const_reference) - */ - template<typename ScalarType, typename std::enable_if< - std::is_scalar<ScalarType>::value, int>::type = 0> - friend bool operator!=(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs != basic_json(rhs)); - } - - /*! - @brief comparison: not equal - @copydoc operator!=(const_reference, const_reference) - */ - template<typename ScalarType, typename std::enable_if< - std::is_scalar<ScalarType>::value, int>::type = 0> - friend bool operator!=(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) != rhs); - } - - /*! - @brief comparison: less than - - Compares whether one JSON value @a lhs is less than another JSON value @a - rhs according to the following rules: - - If @a lhs and @a rhs have the same type, the values are compared using - the default `<` operator. - - Integer and floating-point numbers are automatically converted before - comparison - - In case @a lhs and @a rhs have different types, the values are ignored - and the order of the types is considered, see - @ref operator<(const value_t, const value_t). - - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is less than @a rhs - - @complexity Linear. - - @liveexample{The example demonstrates comparing several JSON - types.,operator__less} - - @since version 1.0.0 - */ - friend bool operator<(const_reference lhs, const_reference rhs) noexcept - { - const auto lhs_type = lhs.type(); - const auto rhs_type = rhs.type(); - - if (lhs_type == rhs_type) - { - switch (lhs_type) - { - case value_t::array: - { - return *lhs.m_value.array < *rhs.m_value.array; - } - case value_t::object: - { - return *lhs.m_value.object < *rhs.m_value.object; - } - case value_t::null: - { - return false; - } - case value_t::string: - { - return *lhs.m_value.string < *rhs.m_value.string; - } - case value_t::boolean: - { - return lhs.m_value.boolean < rhs.m_value.boolean; - } - case value_t::number_integer: - { - return lhs.m_value.number_integer < rhs.m_value.number_integer; - } - case value_t::number_unsigned: - { - return lhs.m_value.number_unsigned < rhs.m_value.number_unsigned; - } - case value_t::number_float: - { - return lhs.m_value.number_float < rhs.m_value.number_float; - } - default: - { - return false; - } - } - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) - { - return static_cast<number_float_t>(lhs.m_value.number_integer) < rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) - { - return lhs.m_value.number_float < static_cast<number_float_t>(rhs.m_value.number_integer); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) - { - return static_cast<number_float_t>(lhs.m_value.number_unsigned) < rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_float < static_cast<number_float_t>(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_integer < static_cast<number_integer_t>(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) - { - return static_cast<number_integer_t>(lhs.m_value.number_unsigned) < rhs.m_value.number_integer; - } - - // We only reach this line if we cannot compare values. In that case, - // we compare types. Note we have to call the operator explicitly, - // because MSVC has problems otherwise. - return operator<(lhs_type, rhs_type); - } - - /*! - @brief comparison: less than or equal - - Compares whether one JSON value @a lhs is less than or equal to another - JSON value by calculating `not (rhs < lhs)`. - - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is less than or equal to @a rhs - - @complexity Linear. - - @liveexample{The example demonstrates comparing several JSON - types.,operator__greater} - - @since version 1.0.0 - */ - friend bool operator<=(const_reference lhs, const_reference rhs) noexcept - { - return not (rhs < lhs); - } - - /*! - @brief comparison: greater than - - Compares whether one JSON value @a lhs is greater than another - JSON value by calculating `not (lhs <= rhs)`. - - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is greater than to @a rhs - - @complexity Linear. - - @liveexample{The example demonstrates comparing several JSON - types.,operator__lessequal} - - @since version 1.0.0 - */ - friend bool operator>(const_reference lhs, const_reference rhs) noexcept - { - return not (lhs <= rhs); - } - - /*! - @brief comparison: greater than or equal - - Compares whether one JSON value @a lhs is greater than or equal to another - JSON value by calculating `not (lhs < rhs)`. - - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is greater than or equal to @a rhs - - @complexity Linear. - - @liveexample{The example demonstrates comparing several JSON - types.,operator__greaterequal} - - @since version 1.0.0 - */ - friend bool operator>=(const_reference lhs, const_reference rhs) noexcept - { - return not (lhs < rhs); - } - - /// @} - - - /////////////////// - // serialization // - /////////////////// - - /// @name serialization - /// @{ - - /*! - @brief serialize to stream - - Serialize the given JSON value @a j to the output stream @a o. The JSON - value will be serialized using the @ref dump member function. The - indentation of the output can be controlled with the member variable - `width` of the output stream @a o. For instance, using the manipulator - `std::setw(4)` on @a o sets the indentation level to `4` and the - serialization result is the same as calling `dump(4)`. - - @param[in,out] o stream to serialize to - @param[in] j JSON value to serialize - - @return the stream @a o - - @complexity Linear. - - @liveexample{The example below shows the serialization with different - parameters to `width` to adjust the indentation level.,operator_serialize} - - @since version 1.0.0 - */ - friend std::ostream& operator<<(std::ostream& o, const basic_json& j) - { - // read width member and use it as indentation parameter if nonzero - const bool pretty_print = (o.width() > 0); - const auto indentation = (pretty_print ? o.width() : 0); - - // reset width to 0 for subsequent calls to this stream - o.width(0); - - // do the actual serialization - j.dump(o, pretty_print, static_cast<unsigned int>(indentation)); - - return o; - } - - /*! - @brief serialize to stream - @copydoc operator<<(std::ostream&, const basic_json&) - */ - friend std::ostream& operator>>(const basic_json& j, std::ostream& o) - { - return o << j; - } - - /// @} - - - ///////////////////// - // deserialization // - ///////////////////// - - /// @name deserialization - /// @{ - - /*! - @brief deserialize from an array - - This function reads from an array of 1-byte values. - - @pre Each element of the container has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** - - @param[in] array array to read from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) - - @return result of the deserialization - - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. - - @note A UTF-8 byte order mark is silently ignored. - - @liveexample{The example below demonstrates the `parse()` function reading - from an array.,parse__array__parser_callback_t} - - @since version 2.0.3 - */ - template<class T, std::size_t N> - static basic_json parse(T (&array)[N], - const parser_callback_t cb = nullptr) - { - // delegate the call to the iterator-range parse overload - return parse(std::begin(array), std::end(array), cb); - } - - /*! - @brief deserialize from string literal - - @tparam CharT character/literal type with size of 1 byte - @param[in] s string literal to read a serialized JSON value from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) - - @return result of the deserialization - - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. - - @note A UTF-8 byte order mark is silently ignored. - @note String containers like `std::string` or @ref string_t can be parsed - with @ref parse(const ContiguousContainer&, const parser_callback_t) - - @liveexample{The example below demonstrates the `parse()` function with - and without callback function.,parse__string__parser_callback_t} - - @sa @ref parse(std::istream&, const parser_callback_t) for a version that - reads from an input stream - - @since version 1.0.0 (originally for @ref string_t) - */ - template<typename CharT, typename std::enable_if< - std::is_pointer<CharT>::value and - std::is_integral<typename std::remove_pointer<CharT>::type>::value and - sizeof(typename std::remove_pointer<CharT>::type) == 1, int>::type = 0> - static basic_json parse(const CharT s, - const parser_callback_t cb = nullptr) - { - return parser(reinterpret_cast<const char*>(s), cb).parse(); - } - - /*! - @brief deserialize from stream - - @param[in,out] i stream to read a serialized JSON value from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) - - @return result of the deserialization - - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. - - @note A UTF-8 byte order mark is silently ignored. - - @liveexample{The example below demonstrates the `parse()` function with - and without callback function.,parse__istream__parser_callback_t} - - @sa @ref parse(const CharT, const parser_callback_t) for a version - that reads from a string - - @since version 1.0.0 - */ - static basic_json parse(std::istream& i, - const parser_callback_t cb = nullptr) - { - return parser(i, cb).parse(); - } - - /*! - @copydoc parse(std::istream&, const parser_callback_t) - */ - static basic_json parse(std::istream&& i, - const parser_callback_t cb = nullptr) - { - return parser(i, cb).parse(); - } - - /*! - @brief deserialize from an iterator range with contiguous storage - - This function reads from an iterator range of a container with contiguous - storage of 1-byte values. Compatible container types include - `std::vector`, `std::string`, `std::array`, `std::valarray`, and - `std::initializer_list`. Furthermore, C-style arrays can be used with - `std::begin()`/`std::end()`. User-defined containers can be used as long - as they implement random-access iterators and a contiguous storage. - - @pre The iterator range is contiguous. Violating this precondition yields - undefined behavior. **This precondition is enforced with an assertion.** - @pre Each element in the range has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** - - @warning There is no way to enforce all preconditions at compile-time. If - the function is called with noncompliant iterators and with - assertions switched off, the behavior is undefined and will most - likely yield segmentation violation. - - @tparam IteratorType iterator of container with contiguous storage - @param[in] first begin of the range to parse (included) - @param[in] last end of the range to parse (excluded) - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) - - @return result of the deserialization - - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. - - @note A UTF-8 byte order mark is silently ignored. - - @liveexample{The example below demonstrates the `parse()` function reading - from an iterator range.,parse__iteratortype__parser_callback_t} - - @since version 2.0.3 - */ - template<class IteratorType, typename std::enable_if< - std::is_base_of< - std::random_access_iterator_tag, - typename std::iterator_traits<IteratorType>::iterator_category>::value, int>::type = 0> - static basic_json parse(IteratorType first, IteratorType last, - const parser_callback_t cb = nullptr) - { - // assertion to check that the iterator range is indeed contiguous, - // see http://stackoverflow.com/a/35008842/266378 for more discussion - assert(std::accumulate(first, last, std::pair<bool, int>(true, 0), - [&first](std::pair<bool, int> res, decltype(*first) val) - { - res.first &= (val == *(std::next(std::addressof(*first), res.second++))); - return res; - }).first); - - // assertion to check that each element is 1 byte long - static_assert(sizeof(typename std::iterator_traits<IteratorType>::value_type) == 1, - "each element in the iterator range must have the size of 1 byte"); - - // if iterator range is empty, create a parser with an empty string - // to generate "unexpected EOF" error message - if (std::distance(first, last) <= 0) - { - return parser("").parse(); - } - - return parser(first, last, cb).parse(); - } - - /*! - @brief deserialize from a container with contiguous storage - - This function reads from a container with contiguous storage of 1-byte - values. Compatible container types include `std::vector`, `std::string`, - `std::array`, and `std::initializer_list`. User-defined containers can be - used as long as they implement random-access iterators and a contiguous - storage. - - @pre The container storage is contiguous. Violating this precondition - yields undefined behavior. **This precondition is enforced with an - assertion.** - @pre Each element of the container has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** - - @warning There is no way to enforce all preconditions at compile-time. If - the function is called with a noncompliant container and with - assertions switched off, the behavior is undefined and will most - likely yield segmentation violation. - - @tparam ContiguousContainer container type with contiguous storage - @param[in] c container to read from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) - - @return result of the deserialization - - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. - - @note A UTF-8 byte order mark is silently ignored. - - @liveexample{The example below demonstrates the `parse()` function reading - from a contiguous container.,parse__contiguouscontainer__parser_callback_t} - - @since version 2.0.3 - */ - template<class ContiguousContainer, typename std::enable_if< - not std::is_pointer<ContiguousContainer>::value and - std::is_base_of< - std::random_access_iterator_tag, - typename std::iterator_traits<decltype(std::begin(std::declval<ContiguousContainer const>()))>::iterator_category>::value - , int>::type = 0> - static basic_json parse(const ContiguousContainer& c, - const parser_callback_t cb = nullptr) - { - // delegate the call to the iterator-range parse overload - return parse(std::begin(c), std::end(c), cb); - } - - /*! - @brief deserialize from stream - - Deserializes an input stream to a JSON value. - - @param[in,out] i input stream to read a serialized JSON value from - @param[in,out] j JSON value to write the deserialized input to - - @throw std::invalid_argument in case of parse errors - - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. - - @note A UTF-8 byte order mark is silently ignored. - - @liveexample{The example below shows how a JSON value is constructed by - reading a serialization from a stream.,operator_deserialize} - - @sa parse(std::istream&, const parser_callback_t) for a variant with a - parser callback function to filter values while parsing - - @since version 1.0.0 - */ - friend std::istream& operator<<(basic_json& j, std::istream& i) - { - j = parser(i).parse(); - return i; - } - - /*! - @brief deserialize from stream - @copydoc operator<<(basic_json&, std::istream&) - */ - friend std::istream& operator>>(std::istream& i, basic_json& j) - { - j = parser(i).parse(); - return i; - } - - /// @} - - ////////////////////////////////////////// - // binary serialization/deserialization // - ////////////////////////////////////////// - - /// @name binary serialization/deserialization support - /// @{ - - private: - /*! - @note Some code in the switch cases has been copied, because otherwise - copilers would complain about implicit fallthrough and there is no - portable attribute to mute such warnings. - */ - template<typename T> - static void add_to_vector(std::vector<uint8_t>& vec, size_t bytes, const T number) - { - assert(bytes == 1 or bytes == 2 or bytes == 4 or bytes == 8); - - switch (bytes) - { - case 8: - { - vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 070) & 0xff)); - vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 060) & 0xff)); - vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 050) & 0xff)); - vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 040) & 0xff)); - vec.push_back(static_cast<uint8_t>((number >> 030) & 0xff)); - vec.push_back(static_cast<uint8_t>((number >> 020) & 0xff)); - vec.push_back(static_cast<uint8_t>((number >> 010) & 0xff)); - vec.push_back(static_cast<uint8_t>(number & 0xff)); - break; - } - - case 4: - { - vec.push_back(static_cast<uint8_t>((number >> 030) & 0xff)); - vec.push_back(static_cast<uint8_t>((number >> 020) & 0xff)); - vec.push_back(static_cast<uint8_t>((number >> 010) & 0xff)); - vec.push_back(static_cast<uint8_t>(number & 0xff)); - break; - } - - case 2: - { - vec.push_back(static_cast<uint8_t>((number >> 010) & 0xff)); - vec.push_back(static_cast<uint8_t>(number & 0xff)); - break; - } - - case 1: - { - vec.push_back(static_cast<uint8_t>(number & 0xff)); - break; - } - } - } - - /*! - @brief take sufficient bytes from a vector to fill an integer variable - - In the context of binary serialization formats, we need to read several - bytes from a byte vector and combine them to multi-byte integral data - types. - - @param[in] vec byte vector to read from - @param[in] current_index the position in the vector after which to read - - @return the next sizeof(T) bytes from @a vec, in reverse order as T - - @tparam T the integral return type - - @throw std::out_of_range if there are less than sizeof(T)+1 bytes in the - vector @a vec to read - - In the for loop, the bytes from the vector are copied in reverse order into - the return value. In the figures below, let sizeof(T)=4 and `i` be the loop - variable. - - Precondition: - - vec: | | | a | b | c | d | T: | | | | | - ^ ^ ^ ^ - current_index i ptr sizeof(T) - - Postcondition: - - vec: | | | a | b | c | d | T: | d | c | b | a | - ^ ^ ^ - | i ptr - current_index - - @sa Code adapted from <http://stackoverflow.com/a/41031865/266378>. - */ - template<typename T> - static T get_from_vector(const std::vector<uint8_t>& vec, const size_t current_index) - { - if (current_index + sizeof(T) + 1 > vec.size()) - { - JSON_THROW(std::out_of_range("cannot read " + std::to_string(sizeof(T)) + " bytes from vector")); - } - - T result; - auto* ptr = reinterpret_cast<uint8_t*>(&result); - for (size_t i = 0; i < sizeof(T); ++i) - { - *ptr++ = vec[current_index + sizeof(T) - i]; - } - return result; - } - - /*! - @brief create a MessagePack serialization of a given JSON value - - This is a straightforward implementation of the MessagePack specification. - - @param[in] j JSON value to serialize - @param[in,out] v byte vector to write the serialization to - - @sa https://github.com/msgpack/msgpack/blob/master/spec.md - */ - static void to_msgpack_internal(const basic_json& j, std::vector<uint8_t>& v) - { - switch (j.type()) - { - case value_t::null: - { - // nil - v.push_back(0xc0); - break; - } - - case value_t::boolean: - { - // true and false - v.push_back(j.m_value.boolean ? 0xc3 : 0xc2); - break; - } - - case value_t::number_integer: - { - if (j.m_value.number_integer >= 0) - { - // MessagePack does not differentiate between positive - // signed integers and unsigned integers. Therefore, we - // used the code from the value_t::number_unsigned case - // here. - if (j.m_value.number_unsigned < 128) - { - // positive fixnum - add_to_vector(v, 1, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= std::numeric_limits<uint8_t>::max()) - { - // uint 8 - v.push_back(0xcc); - add_to_vector(v, 1, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= std::numeric_limits<uint16_t>::max()) - { - // uint 16 - v.push_back(0xcd); - add_to_vector(v, 2, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= std::numeric_limits<uint32_t>::max()) - { - // uint 32 - v.push_back(0xce); - add_to_vector(v, 4, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= std::numeric_limits<uint64_t>::max()) - { - // uint 64 - v.push_back(0xcf); - add_to_vector(v, 8, j.m_value.number_unsigned); - } - } - else - { - if (j.m_value.number_integer >= -32) - { - // negative fixnum - add_to_vector(v, 1, j.m_value.number_integer); - } - else if (j.m_value.number_integer >= std::numeric_limits<int8_t>::min() and j.m_value.number_integer <= std::numeric_limits<int8_t>::max()) - { - // int 8 - v.push_back(0xd0); - add_to_vector(v, 1, j.m_value.number_integer); - } - else if (j.m_value.number_integer >= std::numeric_limits<int16_t>::min() and j.m_value.number_integer <= std::numeric_limits<int16_t>::max()) - { - // int 16 - v.push_back(0xd1); - add_to_vector(v, 2, j.m_value.number_integer); - } - else if (j.m_value.number_integer >= std::numeric_limits<int32_t>::min() and j.m_value.number_integer <= std::numeric_limits<int32_t>::max()) - { - // int 32 - v.push_back(0xd2); - add_to_vector(v, 4, j.m_value.number_integer); - } - else if (j.m_value.number_integer >= std::numeric_limits<int64_t>::min() and j.m_value.number_integer <= std::numeric_limits<int64_t>::max()) - { - // int 64 - v.push_back(0xd3); - add_to_vector(v, 8, j.m_value.number_integer); - } - } - break; - } - - case value_t::number_unsigned: - { - if (j.m_value.number_unsigned < 128) - { - // positive fixnum - add_to_vector(v, 1, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= std::numeric_limits<uint8_t>::max()) - { - // uint 8 - v.push_back(0xcc); - add_to_vector(v, 1, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= std::numeric_limits<uint16_t>::max()) - { - // uint 16 - v.push_back(0xcd); - add_to_vector(v, 2, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= std::numeric_limits<uint32_t>::max()) - { - // uint 32 - v.push_back(0xce); - add_to_vector(v, 4, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= std::numeric_limits<uint64_t>::max()) - { - // uint 64 - v.push_back(0xcf); - add_to_vector(v, 8, j.m_value.number_unsigned); - } - break; - } - - case value_t::number_float: - { - // float 64 - v.push_back(0xcb); - const auto* helper = reinterpret_cast<const uint8_t*>(&(j.m_value.number_float)); - for (size_t i = 0; i < 8; ++i) - { - v.push_back(helper[7 - i]); - } - break; - } - - case value_t::string: - { - const auto N = j.m_value.string->size(); - if (N <= 31) - { - // fixstr - v.push_back(static_cast<uint8_t>(0xa0 | N)); - } - else if (N <= 255) - { - // str 8 - v.push_back(0xd9); - add_to_vector(v, 1, N); - } - else if (N <= 65535) - { - // str 16 - v.push_back(0xda); - add_to_vector(v, 2, N); - } - else if (N <= 4294967295) - { - // str 32 - v.push_back(0xdb); - add_to_vector(v, 4, N); - } - - // append string - std::copy(j.m_value.string->begin(), j.m_value.string->end(), - std::back_inserter(v)); - break; - } - - case value_t::array: - { - const auto N = j.m_value.array->size(); - if (N <= 15) - { - // fixarray - v.push_back(static_cast<uint8_t>(0x90 | N)); - } - else if (N <= 0xffff) - { - // array 16 - v.push_back(0xdc); - add_to_vector(v, 2, N); - } - else if (N <= 0xffffffff) - { - // array 32 - v.push_back(0xdd); - add_to_vector(v, 4, N); - } - - // append each element - for (const auto& el : *j.m_value.array) - { - to_msgpack_internal(el, v); - } - break; - } - - case value_t::object: - { - const auto N = j.m_value.object->size(); - if (N <= 15) - { - // fixmap - v.push_back(static_cast<uint8_t>(0x80 | (N & 0xf))); - } - else if (N <= 65535) - { - // map 16 - v.push_back(0xde); - add_to_vector(v, 2, N); - } - else if (N <= 4294967295) - { - // map 32 - v.push_back(0xdf); - add_to_vector(v, 4, N); - } - - // append each element - for (const auto& el : *j.m_value.object) - { - to_msgpack_internal(el.first, v); - to_msgpack_internal(el.second, v); - } - break; - } - - default: - { - break; - } - } - } - - /*! - @brief create a CBOR serialization of a given JSON value - - This is a straightforward implementation of the CBOR specification. - - @param[in] j JSON value to serialize - @param[in,out] v byte vector to write the serialization to - - @sa https://tools.ietf.org/html/rfc7049 - */ - static void to_cbor_internal(const basic_json& j, std::vector<uint8_t>& v) - { - switch (j.type()) - { - case value_t::null: - { - v.push_back(0xf6); - break; - } - - case value_t::boolean: - { - v.push_back(j.m_value.boolean ? 0xf5 : 0xf4); - break; - } - - case value_t::number_integer: - { - if (j.m_value.number_integer >= 0) - { - // CBOR does not differentiate between positive signed - // integers and unsigned integers. Therefore, we used the - // code from the value_t::number_unsigned case here. - if (j.m_value.number_integer <= 0x17) - { - add_to_vector(v, 1, j.m_value.number_integer); - } - else if (j.m_value.number_integer <= std::numeric_limits<uint8_t>::max()) - { - v.push_back(0x18); - // one-byte uint8_t - add_to_vector(v, 1, j.m_value.number_integer); - } - else if (j.m_value.number_integer <= std::numeric_limits<uint16_t>::max()) - { - v.push_back(0x19); - // two-byte uint16_t - add_to_vector(v, 2, j.m_value.number_integer); - } - else if (j.m_value.number_integer <= std::numeric_limits<uint32_t>::max()) - { - v.push_back(0x1a); - // four-byte uint32_t - add_to_vector(v, 4, j.m_value.number_integer); - } - else - { - v.push_back(0x1b); - // eight-byte uint64_t - add_to_vector(v, 8, j.m_value.number_integer); - } - } - else - { - // The conversions below encode the sign in the first - // byte, and the value is converted to a positive number. - const auto positive_number = -1 - j.m_value.number_integer; - if (j.m_value.number_integer >= -24) - { - v.push_back(static_cast<uint8_t>(0x20 + positive_number)); - } - else if (positive_number <= std::numeric_limits<uint8_t>::max()) - { - // int 8 - v.push_back(0x38); - add_to_vector(v, 1, positive_number); - } - else if (positive_number <= std::numeric_limits<uint16_t>::max()) - { - // int 16 - v.push_back(0x39); - add_to_vector(v, 2, positive_number); - } - else if (positive_number <= std::numeric_limits<uint32_t>::max()) - { - // int 32 - v.push_back(0x3a); - add_to_vector(v, 4, positive_number); - } - else - { - // int 64 - v.push_back(0x3b); - add_to_vector(v, 8, positive_number); - } - } - break; - } - - case value_t::number_unsigned: - { - if (j.m_value.number_unsigned <= 0x17) - { - v.push_back(static_cast<uint8_t>(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= 0xff) - { - v.push_back(0x18); - // one-byte uint8_t - add_to_vector(v, 1, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= 0xffff) - { - v.push_back(0x19); - // two-byte uint16_t - add_to_vector(v, 2, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= 0xffffffff) - { - v.push_back(0x1a); - // four-byte uint32_t - add_to_vector(v, 4, j.m_value.number_unsigned); - } - else if (j.m_value.number_unsigned <= 0xffffffffffffffff) - { - v.push_back(0x1b); - // eight-byte uint64_t - add_to_vector(v, 8, j.m_value.number_unsigned); - } - break; - } - - case value_t::number_float: - { - // Double-Precision Float - v.push_back(0xfb); - const auto* helper = reinterpret_cast<const uint8_t*>(&(j.m_value.number_float)); - for (size_t i = 0; i < 8; ++i) - { - v.push_back(helper[7 - i]); - } - break; - } - - case value_t::string: - { - const auto N = j.m_value.string->size(); - if (N <= 0x17) - { - v.push_back(0x60 + static_cast<uint8_t>(N)); // 1 byte for string + size - } - else if (N <= 0xff) - { - v.push_back(0x78); // one-byte uint8_t for N - add_to_vector(v, 1, N); - } - else if (N <= 0xffff) - { - v.push_back(0x79); // two-byte uint16_t for N - add_to_vector(v, 2, N); - } - else if (N <= 0xffffffff) - { - v.push_back(0x7a); // four-byte uint32_t for N - add_to_vector(v, 4, N); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - v.push_back(0x7b); // eight-byte uint64_t for N - add_to_vector(v, 8, N); - } - // LCOV_EXCL_STOP - - // append string - std::copy(j.m_value.string->begin(), j.m_value.string->end(), - std::back_inserter(v)); - break; - } - - case value_t::array: - { - const auto N = j.m_value.array->size(); - if (N <= 0x17) - { - v.push_back(0x80 + static_cast<uint8_t>(N)); // 1 byte for array + size - } - else if (N <= 0xff) - { - v.push_back(0x98); // one-byte uint8_t for N - add_to_vector(v, 1, N); - } - else if (N <= 0xffff) - { - v.push_back(0x99); // two-byte uint16_t for N - add_to_vector(v, 2, N); - } - else if (N <= 0xffffffff) - { - v.push_back(0x9a); // four-byte uint32_t for N - add_to_vector(v, 4, N); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - v.push_back(0x9b); // eight-byte uint64_t for N - add_to_vector(v, 8, N); - } - // LCOV_EXCL_STOP - - // append each element - for (const auto& el : *j.m_value.array) - { - to_cbor_internal(el, v); - } - break; - } - - case value_t::object: - { - const auto N = j.m_value.object->size(); - if (N <= 0x17) - { - v.push_back(0xa0 + static_cast<uint8_t>(N)); // 1 byte for object + size - } - else if (N <= 0xff) - { - v.push_back(0xb8); - add_to_vector(v, 1, N); // one-byte uint8_t for N - } - else if (N <= 0xffff) - { - v.push_back(0xb9); - add_to_vector(v, 2, N); // two-byte uint16_t for N - } - else if (N <= 0xffffffff) - { - v.push_back(0xba); - add_to_vector(v, 4, N); // four-byte uint32_t for N - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - v.push_back(0xbb); - add_to_vector(v, 8, N); // eight-byte uint64_t for N - } - // LCOV_EXCL_STOP - - // append each element - for (const auto& el : *j.m_value.object) - { - to_cbor_internal(el.first, v); - to_cbor_internal(el.second, v); - } - break; - } - - default: - { - break; - } - } - } - - - /* - @brief checks if given lengths do not exceed the size of a given vector - - To secure the access to the byte vector during CBOR/MessagePack - deserialization, bytes are copied from the vector into buffers. This - function checks if the number of bytes to copy (@a len) does not exceed - the size @s size of the vector. Additionally, an @a offset is given from - where to start reading the bytes. - - This function checks whether reading the bytes is safe; that is, offset is - a valid index in the vector, offset+len - - @param[in] size size of the byte vector - @param[in] len number of bytes to read - @param[in] offset offset where to start reading - - vec: x x x x x X X X X X - ^ ^ ^ - 0 offset len - - @throws out_of_range if `len > v.size()` - */ - static void check_length(const size_t size, const size_t len, const size_t offset) - { - // simple case: requested length is greater than the vector's length - if (len > size or offset > size) - { - JSON_THROW(std::out_of_range("len out of range")); - } - - // second case: adding offset would result in overflow - if ((size > (std::numeric_limits<size_t>::max() - offset))) - { - JSON_THROW(std::out_of_range("len+offset out of range")); - } - - // last case: reading past the end of the vector - if (len + offset > size) - { - JSON_THROW(std::out_of_range("len+offset out of range")); - } - } - - /*! - @brief create a JSON value from a given MessagePack vector - - @param[in] v MessagePack serialization - @param[in] idx byte index to start reading from @a v - - @return deserialized JSON value - - @throw std::invalid_argument if unsupported features from MessagePack were - used in the given vector @a v or if the input is not valid MessagePack - @throw std::out_of_range if the given vector ends prematurely - - @sa https://github.com/msgpack/msgpack/blob/master/spec.md - */ - static basic_json from_msgpack_internal(const std::vector<uint8_t>& v, size_t& idx) - { - // make sure reading 1 byte is safe - check_length(v.size(), 1, idx); - - // store and increment index - const size_t current_idx = idx++; - - if (v[current_idx] <= 0xbf) - { - if (v[current_idx] <= 0x7f) // positive fixint - { - return v[current_idx]; - } - if (v[current_idx] <= 0x8f) // fixmap - { - basic_json result = value_t::object; - const size_t len = v[current_idx] & 0x0f; - for (size_t i = 0; i < len; ++i) - { - std::string key = from_msgpack_internal(v, idx); - result[key] = from_msgpack_internal(v, idx); - } - return result; - } - else if (v[current_idx] <= 0x9f) // fixarray - { - basic_json result = value_t::array; - const size_t len = v[current_idx] & 0x0f; - for (size_t i = 0; i < len; ++i) - { - result.push_back(from_msgpack_internal(v, idx)); - } - return result; - } - else // fixstr - { - const size_t len = v[current_idx] & 0x1f; - const size_t offset = current_idx + 1; - idx += len; // skip content bytes - check_length(v.size(), len, offset); - return std::string(reinterpret_cast<const char*>(v.data()) + offset, len); - } - } - else if (v[current_idx] >= 0xe0) // negative fixint - { - return static_cast<int8_t>(v[current_idx]); - } - else - { - switch (v[current_idx]) - { - case 0xc0: // nil - { - return value_t::null; - } - - case 0xc2: // false - { - return false; - } - - case 0xc3: // true - { - return true; - } - - case 0xca: // float 32 - { - // copy bytes in reverse order into the double variable - float res; - for (size_t byte = 0; byte < sizeof(float); ++byte) - { - reinterpret_cast<uint8_t*>(&res)[sizeof(float) - byte - 1] = v.at(current_idx + 1 + byte); - } - idx += sizeof(float); // skip content bytes - return res; - } - - case 0xcb: // float 64 - { - // copy bytes in reverse order into the double variable - double res; - for (size_t byte = 0; byte < sizeof(double); ++byte) - { - reinterpret_cast<uint8_t*>(&res)[sizeof(double) - byte - 1] = v.at(current_idx + 1 + byte); - } - idx += sizeof(double); // skip content bytes - return res; - } - - case 0xcc: // uint 8 - { - idx += 1; // skip content byte - return get_from_vector<uint8_t>(v, current_idx); - } - - case 0xcd: // uint 16 - { - idx += 2; // skip 2 content bytes - return get_from_vector<uint16_t>(v, current_idx); - } - - case 0xce: // uint 32 - { - idx += 4; // skip 4 content bytes - return get_from_vector<uint32_t>(v, current_idx); - } - - case 0xcf: // uint 64 - { - idx += 8; // skip 8 content bytes - return get_from_vector<uint64_t>(v, current_idx); - } - - case 0xd0: // int 8 - { - idx += 1; // skip content byte - return get_from_vector<int8_t>(v, current_idx); - } - - case 0xd1: // int 16 - { - idx += 2; // skip 2 content bytes - return get_from_vector<int16_t>(v, current_idx); - } - - case 0xd2: // int 32 - { - idx += 4; // skip 4 content bytes - return get_from_vector<int32_t>(v, current_idx); - } - - case 0xd3: // int 64 - { - idx += 8; // skip 8 content bytes - return get_from_vector<int64_t>(v, current_idx); - } - - case 0xd9: // str 8 - { - const auto len = static_cast<size_t>(get_from_vector<uint8_t>(v, current_idx)); - const size_t offset = current_idx + 2; - idx += len + 1; // skip size byte + content bytes - check_length(v.size(), len, offset); - return std::string(reinterpret_cast<const char*>(v.data()) + offset, len); - } - - case 0xda: // str 16 - { - const auto len = static_cast<size_t>(get_from_vector<uint16_t>(v, current_idx)); - const size_t offset = current_idx + 3; - idx += len + 2; // skip 2 size bytes + content bytes - check_length(v.size(), len, offset); - return std::string(reinterpret_cast<const char*>(v.data()) + offset, len); - } - - case 0xdb: // str 32 - { - const auto len = static_cast<size_t>(get_from_vector<uint32_t>(v, current_idx)); - const size_t offset = current_idx + 5; - idx += len + 4; // skip 4 size bytes + content bytes - check_length(v.size(), len, offset); - return std::string(reinterpret_cast<const char*>(v.data()) + offset, len); - } - - case 0xdc: // array 16 - { - basic_json result = value_t::array; - const auto len = static_cast<size_t>(get_from_vector<uint16_t>(v, current_idx)); - idx += 2; // skip 2 size bytes - for (size_t i = 0; i < len; ++i) - { - result.push_back(from_msgpack_internal(v, idx)); - } - return result; - } - - case 0xdd: // array 32 - { - basic_json result = value_t::array; - const auto len = static_cast<size_t>(get_from_vector<uint32_t>(v, current_idx)); - idx += 4; // skip 4 size bytes - for (size_t i = 0; i < len; ++i) - { - result.push_back(from_msgpack_internal(v, idx)); - } - return result; - } - - case 0xde: // map 16 - { - basic_json result = value_t::object; - const auto len = static_cast<size_t>(get_from_vector<uint16_t>(v, current_idx)); - idx += 2; // skip 2 size bytes - for (size_t i = 0; i < len; ++i) - { - std::string key = from_msgpack_internal(v, idx); - result[key] = from_msgpack_internal(v, idx); - } - return result; - } - - case 0xdf: // map 32 - { - basic_json result = value_t::object; - const auto len = static_cast<size_t>(get_from_vector<uint32_t>(v, current_idx)); - idx += 4; // skip 4 size bytes - for (size_t i = 0; i < len; ++i) - { - std::string key = from_msgpack_internal(v, idx); - result[key] = from_msgpack_internal(v, idx); - } - return result; - } - - default: - { - JSON_THROW(std::invalid_argument("error parsing a msgpack @ " + std::to_string(current_idx) + ": " + std::to_string(static_cast<int>(v[current_idx])))); - } - } - } - } - - /*! - @brief create a JSON value from a given CBOR vector - - @param[in] v CBOR serialization - @param[in] idx byte index to start reading from @a v - - @return deserialized JSON value - - @throw std::invalid_argument if unsupported features from CBOR were used in - the given vector @a v or if the input is not valid CBOR - @throw std::out_of_range if the given vector ends prematurely - - @sa https://tools.ietf.org/html/rfc7049 - */ - static basic_json from_cbor_internal(const std::vector<uint8_t>& v, size_t& idx) - { - // store and increment index - const size_t current_idx = idx++; - - switch (v.at(current_idx)) - { - // Integer 0x00..0x17 (0..23) - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - { - return v[current_idx]; - } - - case 0x18: // Unsigned integer (one-byte uint8_t follows) - { - idx += 1; // skip content byte - return get_from_vector<uint8_t>(v, current_idx); - } - - case 0x19: // Unsigned integer (two-byte uint16_t follows) - { - idx += 2; // skip 2 content bytes - return get_from_vector<uint16_t>(v, current_idx); - } - - case 0x1a: // Unsigned integer (four-byte uint32_t follows) - { - idx += 4; // skip 4 content bytes - return get_from_vector<uint32_t>(v, current_idx); - } - - case 0x1b: // Unsigned integer (eight-byte uint64_t follows) - { - idx += 8; // skip 8 content bytes - return get_from_vector<uint64_t>(v, current_idx); - } - - // Negative integer -1-0x00..-1-0x17 (-1..-24) - case 0x20: - case 0x21: - case 0x22: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - { - return static_cast<int8_t>(0x20 - 1 - v[current_idx]); - } - - case 0x38: // Negative integer (one-byte uint8_t follows) - { - idx += 1; // skip content byte - // must be uint8_t ! - return static_cast<number_integer_t>(-1) - get_from_vector<uint8_t>(v, current_idx); - } - - case 0x39: // Negative integer -1-n (two-byte uint16_t follows) - { - idx += 2; // skip 2 content bytes - return static_cast<number_integer_t>(-1) - get_from_vector<uint16_t>(v, current_idx); - } - - case 0x3a: // Negative integer -1-n (four-byte uint32_t follows) - { - idx += 4; // skip 4 content bytes - return static_cast<number_integer_t>(-1) - get_from_vector<uint32_t>(v, current_idx); - } - - case 0x3b: // Negative integer -1-n (eight-byte uint64_t follows) - { - idx += 8; // skip 8 content bytes - return static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(get_from_vector<uint64_t>(v, current_idx)); - } - - // UTF-8 string (0x00..0x17 bytes follow) - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - { - const auto len = static_cast<size_t>(v[current_idx] - 0x60); - const size_t offset = current_idx + 1; - idx += len; // skip content bytes - check_length(v.size(), len, offset); - return std::string(reinterpret_cast<const char*>(v.data()) + offset, len); - } - - case 0x78: // UTF-8 string (one-byte uint8_t for n follows) - { - const auto len = static_cast<size_t>(get_from_vector<uint8_t>(v, current_idx)); - const size_t offset = current_idx + 2; - idx += len + 1; // skip size byte + content bytes - check_length(v.size(), len, offset); - return std::string(reinterpret_cast<const char*>(v.data()) + offset, len); - } - - case 0x79: // UTF-8 string (two-byte uint16_t for n follow) - { - const auto len = static_cast<size_t>(get_from_vector<uint16_t>(v, current_idx)); - const size_t offset = current_idx + 3; - idx += len + 2; // skip 2 size bytes + content bytes - check_length(v.size(), len, offset); - return std::string(reinterpret_cast<const char*>(v.data()) + offset, len); - } - - case 0x7a: // UTF-8 string (four-byte uint32_t for n follow) - { - const auto len = static_cast<size_t>(get_from_vector<uint32_t>(v, current_idx)); - const size_t offset = current_idx + 5; - idx += len + 4; // skip 4 size bytes + content bytes - check_length(v.size(), len, offset); - return std::string(reinterpret_cast<const char*>(v.data()) + offset, len); - } - - case 0x7b: // UTF-8 string (eight-byte uint64_t for n follow) - { - const auto len = static_cast<size_t>(get_from_vector<uint64_t>(v, current_idx)); - const size_t offset = current_idx + 9; - idx += len + 8; // skip 8 size bytes + content bytes - check_length(v.size(), len, offset); - return std::string(reinterpret_cast<const char*>(v.data()) + offset, len); - } - - case 0x7f: // UTF-8 string (indefinite length) - { - std::string result; - while (v.at(idx) != 0xff) - { - string_t s = from_cbor_internal(v, idx); - result += s; - } - // skip break byte (0xFF) - idx += 1; - return result; - } - - // array (0x00..0x17 data items follow) - case 0x80: - case 0x81: - case 0x82: - case 0x83: - case 0x84: - case 0x85: - case 0x86: - case 0x87: - case 0x88: - case 0x89: - case 0x8a: - case 0x8b: - case 0x8c: - case 0x8d: - case 0x8e: - case 0x8f: - case 0x90: - case 0x91: - case 0x92: - case 0x93: - case 0x94: - case 0x95: - case 0x96: - case 0x97: - { - basic_json result = value_t::array; - const auto len = static_cast<size_t>(v[current_idx] - 0x80); - for (size_t i = 0; i < len; ++i) - { - result.push_back(from_cbor_internal(v, idx)); - } - return result; - } - - case 0x98: // array (one-byte uint8_t for n follows) - { - basic_json result = value_t::array; - const auto len = static_cast<size_t>(get_from_vector<uint8_t>(v, current_idx)); - idx += 1; // skip 1 size byte - for (size_t i = 0; i < len; ++i) - { - result.push_back(from_cbor_internal(v, idx)); - } - return result; - } - - case 0x99: // array (two-byte uint16_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast<size_t>(get_from_vector<uint16_t>(v, current_idx)); - idx += 2; // skip 4 size bytes - for (size_t i = 0; i < len; ++i) - { - result.push_back(from_cbor_internal(v, idx)); - } - return result; - } - - case 0x9a: // array (four-byte uint32_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast<size_t>(get_from_vector<uint32_t>(v, current_idx)); - idx += 4; // skip 4 size bytes - for (size_t i = 0; i < len; ++i) - { - result.push_back(from_cbor_internal(v, idx)); - } - return result; - } - - case 0x9b: // array (eight-byte uint64_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast<size_t>(get_from_vector<uint64_t>(v, current_idx)); - idx += 8; // skip 8 size bytes - for (size_t i = 0; i < len; ++i) - { - result.push_back(from_cbor_internal(v, idx)); - } - return result; - } - - case 0x9f: // array (indefinite length) - { - basic_json result = value_t::array; - while (v.at(idx) != 0xff) - { - result.push_back(from_cbor_internal(v, idx)); - } - // skip break byte (0xFF) - idx += 1; - return result; - } - - // map (0x00..0x17 pairs of data items follow) - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - { - basic_json result = value_t::object; - const auto len = static_cast<size_t>(v[current_idx] - 0xa0); - for (size_t i = 0; i < len; ++i) - { - std::string key = from_cbor_internal(v, idx); - result[key] = from_cbor_internal(v, idx); - } - return result; - } - - case 0xb8: // map (one-byte uint8_t for n follows) - { - basic_json result = value_t::object; - const auto len = static_cast<size_t>(get_from_vector<uint8_t>(v, current_idx)); - idx += 1; // skip 1 size byte - for (size_t i = 0; i < len; ++i) - { - std::string key = from_cbor_internal(v, idx); - result[key] = from_cbor_internal(v, idx); - } - return result; - } - - case 0xb9: // map (two-byte uint16_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast<size_t>(get_from_vector<uint16_t>(v, current_idx)); - idx += 2; // skip 2 size bytes - for (size_t i = 0; i < len; ++i) - { - std::string key = from_cbor_internal(v, idx); - result[key] = from_cbor_internal(v, idx); - } - return result; - } - - case 0xba: // map (four-byte uint32_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast<size_t>(get_from_vector<uint32_t>(v, current_idx)); - idx += 4; // skip 4 size bytes - for (size_t i = 0; i < len; ++i) - { - std::string key = from_cbor_internal(v, idx); - result[key] = from_cbor_internal(v, idx); - } - return result; - } - - case 0xbb: // map (eight-byte uint64_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast<size_t>(get_from_vector<uint64_t>(v, current_idx)); - idx += 8; // skip 8 size bytes - for (size_t i = 0; i < len; ++i) - { - std::string key = from_cbor_internal(v, idx); - result[key] = from_cbor_internal(v, idx); - } - return result; - } - - case 0xbf: // map (indefinite length) - { - basic_json result = value_t::object; - while (v.at(idx) != 0xff) - { - std::string key = from_cbor_internal(v, idx); - result[key] = from_cbor_internal(v, idx); - } - // skip break byte (0xFF) - idx += 1; - return result; - } - - case 0xf4: // false - { - return false; - } - - case 0xf5: // true - { - return true; - } - - case 0xf6: // null - { - return value_t::null; - } - - case 0xf9: // Half-Precision Float (two-byte IEEE 754) - { - idx += 2; // skip two content bytes - - // code from RFC 7049, Appendix D, Figure 3: - // As half-precision floating-point numbers were only added to - // IEEE 754 in 2008, today's programming platforms often still - // only have limited support for them. It is very easy to - // include at least decoding support for them even without such - // support. An example of a small decoder for half-precision - // floating-point numbers in the C language is shown in Fig. 3. - const int half = (v.at(current_idx + 1) << 8) + v.at(current_idx + 2); - const int exp = (half >> 10) & 0x1f; - const int mant = half & 0x3ff; - double val; - if (exp == 0) - { - val = std::ldexp(mant, -24); - } - else if (exp != 31) - { - val = std::ldexp(mant + 1024, exp - 25); - } - else - { - val = mant == 0 - ? std::numeric_limits<double>::infinity() - : std::numeric_limits<double>::quiet_NaN(); - } - return (half & 0x8000) != 0 ? -val : val; - } - - case 0xfa: // Single-Precision Float (four-byte IEEE 754) - { - // copy bytes in reverse order into the float variable - float res; - for (size_t byte = 0; byte < sizeof(float); ++byte) - { - reinterpret_cast<uint8_t*>(&res)[sizeof(float) - byte - 1] = v.at(current_idx + 1 + byte); - } - idx += sizeof(float); // skip content bytes - return res; - } - - case 0xfb: // Double-Precision Float (eight-byte IEEE 754) - { - // copy bytes in reverse order into the double variable - double res; - for (size_t byte = 0; byte < sizeof(double); ++byte) - { - reinterpret_cast<uint8_t*>(&res)[sizeof(double) - byte - 1] = v.at(current_idx + 1 + byte); - } - idx += sizeof(double); // skip content bytes - return res; - } - - default: // anything else (0xFF is handled inside the other types) - { - JSON_THROW(std::invalid_argument("error parsing a CBOR @ " + std::to_string(current_idx) + ": " + std::to_string(static_cast<int>(v[current_idx])))); - } - } - } - - public: - /*! - @brief create a MessagePack serialization of a given JSON value - - Serializes a given JSON value @a j to a byte vector using the MessagePack - serialization format. MessagePack is a binary serialization format which - aims to be more compact than JSON itself, yet more efficient to parse. - - @param[in] j JSON value to serialize - @return MessagePack serialization as byte vector - - @complexity Linear in the size of the JSON value @a j. - - @liveexample{The example shows the serialization of a JSON value to a byte - vector in MessagePack format.,to_msgpack} - - @sa http://msgpack.org - @sa @ref from_msgpack(const std::vector<uint8_t>&, const size_t) for the - analogous deserialization - @sa @ref to_cbor(const basic_json& for the related CBOR format - - @since version 2.0.9 - */ - static std::vector<uint8_t> to_msgpack(const basic_json& j) - { - std::vector<uint8_t> result; - to_msgpack_internal(j, result); - return result; - } - - /*! - @brief create a JSON value from a byte vector in MessagePack format - - Deserializes a given byte vector @a v to a JSON value using the MessagePack - serialization format. - - @param[in] v a byte vector in MessagePack format - @param[in] start_index the index to start reading from @a v (0 by default) - @return deserialized JSON value - - @throw std::invalid_argument if unsupported features from MessagePack were - used in the given vector @a v or if the input is not valid MessagePack - @throw std::out_of_range if the given vector ends prematurely - - @complexity Linear in the size of the byte vector @a v. - - @liveexample{The example shows the deserialization of a byte vector in - MessagePack format to a JSON value.,from_msgpack} - - @sa http://msgpack.org - @sa @ref to_msgpack(const basic_json&) for the analogous serialization - @sa @ref from_cbor(const std::vector<uint8_t>&, const size_t) for the - related CBOR format - - @since version 2.0.9, parameter @a start_index since 2.1.1 - */ - static basic_json from_msgpack(const std::vector<uint8_t>& v, - const size_t start_index = 0) - { - size_t i = start_index; - return from_msgpack_internal(v, i); - } - - /*! - @brief create a MessagePack serialization of a given JSON value - - Serializes a given JSON value @a j to a byte vector using the CBOR (Concise - Binary Object Representation) serialization format. CBOR is a binary - serialization format which aims to be more compact than JSON itself, yet - more efficient to parse. - - @param[in] j JSON value to serialize - @return MessagePack serialization as byte vector - - @complexity Linear in the size of the JSON value @a j. - - @liveexample{The example shows the serialization of a JSON value to a byte - vector in CBOR format.,to_cbor} - - @sa http://cbor.io - @sa @ref from_cbor(const std::vector<uint8_t>&, const size_t) for the - analogous deserialization - @sa @ref to_msgpack(const basic_json& for the related MessagePack format - - @since version 2.0.9 - */ - static std::vector<uint8_t> to_cbor(const basic_json& j) - { - std::vector<uint8_t> result; - to_cbor_internal(j, result); - return result; - } - - /*! - @brief create a JSON value from a byte vector in CBOR format - - Deserializes a given byte vector @a v to a JSON value using the CBOR - (Concise Binary Object Representation) serialization format. - - @param[in] v a byte vector in CBOR format - @param[in] start_index the index to start reading from @a v (0 by default) - @return deserialized JSON value - - @throw std::invalid_argument if unsupported features from CBOR were used in - the given vector @a v or if the input is not valid MessagePack - @throw std::out_of_range if the given vector ends prematurely - - @complexity Linear in the size of the byte vector @a v. - - @liveexample{The example shows the deserialization of a byte vector in CBOR - format to a JSON value.,from_cbor} - - @sa http://cbor.io - @sa @ref to_cbor(const basic_json&) for the analogous serialization - @sa @ref from_msgpack(const std::vector<uint8_t>&, const size_t) for the - related MessagePack format - - @since version 2.0.9, parameter @a start_index since 2.1.1 - */ - static basic_json from_cbor(const std::vector<uint8_t>& v, - const size_t start_index = 0) - { - size_t i = start_index; - return from_cbor_internal(v, i); - } - - /// @} - - /////////////////////////// - // convenience functions // - /////////////////////////// - - /*! - @brief return the type as string - - Returns the type name as string to be used in error messages - usually to - indicate that a function was called on a wrong JSON type. - - @return basically a string representation of a the @a m_type member - - @complexity Constant. - - @liveexample{The following code exemplifies `type_name()` for all JSON - types.,type_name} - - @since version 1.0.0, public since 2.1.0 - */ - std::string type_name() const - { - { - switch (m_type) - { - case value_t::null: - return "null"; - case value_t::object: - return "object"; - case value_t::array: - return "array"; - case value_t::string: - return "string"; - case value_t::boolean: - return "boolean"; - case value_t::discarded: - return "discarded"; - default: - return "number"; - } - } - } - - private: - /*! - @brief calculates the extra space to escape a JSON string - - @param[in] s the string to escape - @return the number of characters required to escape string @a s - - @complexity Linear in the length of string @a s. - */ - static std::size_t extra_space(const string_t& s) noexcept - { - return std::accumulate(s.begin(), s.end(), size_t{}, - [](size_t res, typename string_t::value_type c) - { - switch (c) - { - case '"': - case '\\': - case '\b': - case '\f': - case '\n': - case '\r': - case '\t': - { - // from c (1 byte) to \x (2 bytes) - return res + 1; - } - - default: - { - if (c >= 0x00 and c <= 0x1f) - { - // from c (1 byte) to \uxxxx (6 bytes) - return res + 5; - } - - return res; - } - } - }); - } - - /*! - @brief escape a string - - Escape a string by replacing certain special characters by a sequence of - an escape character (backslash) and another character and other control - characters by a sequence of "\u" followed by a four-digit hex - representation. - - @param[in] s the string to escape - @return the escaped string - - @complexity Linear in the length of string @a s. - */ - static string_t escape_string(const string_t& s) - { - const auto space = extra_space(s); - if (space == 0) - { - return s; - } - - // create a result string of necessary size - string_t result(s.size() + space, '\\'); - std::size_t pos = 0; - - for (const auto& c : s) - { - switch (c) - { - // quotation mark (0x22) - case '"': - { - result[pos + 1] = '"'; - pos += 2; - break; - } - - // reverse solidus (0x5c) - case '\\': - { - // nothing to change - pos += 2; - break; - } - - // backspace (0x08) - case '\b': - { - result[pos + 1] = 'b'; - pos += 2; - break; - } - - // formfeed (0x0c) - case '\f': - { - result[pos + 1] = 'f'; - pos += 2; - break; - } - - // newline (0x0a) - case '\n': - { - result[pos + 1] = 'n'; - pos += 2; - break; - } - - // carriage return (0x0d) - case '\r': - { - result[pos + 1] = 'r'; - pos += 2; - break; - } - - // horizontal tab (0x09) - case '\t': - { - result[pos + 1] = 't'; - pos += 2; - break; - } - - default: - { - if (c >= 0x00 and c <= 0x1f) - { - // convert a number 0..15 to its hex representation - // (0..f) - static const char hexify[16] = - { - '0', '1', '2', '3', '4', '5', '6', '7', - '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' - }; - - // print character c as \uxxxx - for (const char m : - { 'u', '0', '0', hexify[c >> 4], hexify[c & 0x0f] - }) - { - result[++pos] = m; - } - - ++pos; - } - else - { - // all other characters are added as-is - result[pos++] = c; - } - break; - } - } - } - - return result; - } - - - /*! - @brief locale-independent serialization for built-in arithmetic types - */ - struct numtostr - { - public: - template<typename NumberType> - numtostr(NumberType value) - { - x_write(value, std::is_integral<NumberType>()); - } - - const char* c_str() const - { - return m_buf.data(); - } - - private: - /// a (hopefully) large enough character buffer - std::array < char, 64 > m_buf{{}}; - - template<typename NumberType> - void x_write(NumberType x, /*is_integral=*/std::true_type) - { - // special case for "0" - if (x == 0) - { - m_buf[0] = '0'; - return; - } - - const bool is_negative = x < 0; - size_t i = 0; - - // spare 1 byte for '\0' - while (x != 0 and i < m_buf.size() - 1) - { - const auto digit = std::labs(static_cast<long>(x % 10)); - m_buf[i++] = static_cast<char>('0' + digit); - x /= 10; - } - - // make sure the number has been processed completely - assert(x == 0); - - if (is_negative) - { - // make sure there is capacity for the '-' - assert(i < m_buf.size() - 2); - m_buf[i++] = '-'; - } - - std::reverse(m_buf.begin(), m_buf.begin() + i); - } - - template<typename NumberType> - void x_write(NumberType x, /*is_integral=*/std::false_type) - { - // special case for 0.0 and -0.0 - if (x == 0) - { - size_t i = 0; - if (std::signbit(x)) - { - m_buf[i++] = '-'; - } - m_buf[i++] = '0'; - m_buf[i++] = '.'; - m_buf[i] = '0'; - return; - } - - // get number of digits for a text -> float -> text round-trip - static constexpr auto d = std::numeric_limits<NumberType>::digits10; - - // the actual conversion - const auto written_bytes = snprintf(m_buf.data(), m_buf.size(), "%.*g", d, x); - - // negative value indicates an error - assert(written_bytes > 0); - // check if buffer was large enough - assert(static_cast<size_t>(written_bytes) < m_buf.size()); - - // read information from locale - const auto loc = localeconv(); - assert(loc != nullptr); - const char thousands_sep = !loc->thousands_sep ? '\0' - : loc->thousands_sep[0]; - - const char decimal_point = !loc->decimal_point ? '\0' - : loc->decimal_point[0]; - - // erase thousands separator - if (thousands_sep != '\0') - { - const auto end = std::remove(m_buf.begin(), m_buf.begin() + written_bytes, thousands_sep); - std::fill(end, m_buf.end(), '\0'); - } - - // convert decimal point to '.' - if (decimal_point != '\0' and decimal_point != '.') - { - for (auto& c : m_buf) - { - if (c == decimal_point) - { - c = '.'; - break; - } - } - } - - // determine if need to append ".0" - size_t i = 0; - bool value_is_int_like = true; - for (i = 0; i < m_buf.size(); ++i) - { - // break when end of number is reached - if (m_buf[i] == '\0') - { - break; - } - - // check if we find non-int character - value_is_int_like = value_is_int_like and m_buf[i] != '.' and - m_buf[i] != 'e' and m_buf[i] != 'E'; - } - - if (value_is_int_like) - { - // there must be 2 bytes left for ".0" - assert((i + 2) < m_buf.size()); - // we write to the end of the number - assert(m_buf[i] == '\0'); - assert(m_buf[i - 1] != '\0'); - - // add ".0" - m_buf[i] = '.'; - m_buf[i + 1] = '0'; - - // the resulting string is properly terminated - assert(m_buf[i + 2] == '\0'); - } - } - }; - - - /*! - @brief internal implementation of the serialization function - - This function is called by the public member function dump and organizes - the serialization internally. The indentation level is propagated as - additional parameter. In case of arrays and objects, the function is - called recursively. Note that - - - strings and object keys are escaped using `escape_string()` - - integer numbers are converted implicitly via `operator<<` - - floating-point numbers are converted to a string using `"%g"` format - - @param[out] o stream to write to - @param[in] pretty_print whether the output shall be pretty-printed - @param[in] indent_step the indent level - @param[in] current_indent the current indent level (only used internally) - */ - void dump(std::ostream& o, - const bool pretty_print, - const unsigned int indent_step, - const unsigned int current_indent = 0) const - { - // variable to hold indentation for recursive calls - unsigned int new_indent = current_indent; - - switch (m_type) - { - case value_t::object: - { - if (m_value.object->empty()) - { - o << "{}"; - return; - } - - o << "{"; - - // increase indentation - if (pretty_print) - { - new_indent += indent_step; - o << "\n"; - } - - for (auto i = m_value.object->cbegin(); i != m_value.object->cend(); ++i) - { - if (i != m_value.object->cbegin()) - { - o << (pretty_print ? ",\n" : ","); - } - o << string_t(new_indent, ' ') << "\"" - << escape_string(i->first) << "\":" - << (pretty_print ? " " : ""); - i->second.dump(o, pretty_print, indent_step, new_indent); - } - - // decrease indentation - if (pretty_print) - { - new_indent -= indent_step; - o << "\n"; - } - - o << string_t(new_indent, ' ') + "}"; - return; - } - - case value_t::array: - { - if (m_value.array->empty()) - { - o << "[]"; - return; - } - - o << "["; - - // increase indentation - if (pretty_print) - { - new_indent += indent_step; - o << "\n"; - } - - for (auto i = m_value.array->cbegin(); i != m_value.array->cend(); ++i) - { - if (i != m_value.array->cbegin()) - { - o << (pretty_print ? ",\n" : ","); - } - o << string_t(new_indent, ' '); - i->dump(o, pretty_print, indent_step, new_indent); - } - - // decrease indentation - if (pretty_print) - { - new_indent -= indent_step; - o << "\n"; - } - - o << string_t(new_indent, ' ') << "]"; - return; - } - - case value_t::string: - { - o << string_t("\"") << escape_string(*m_value.string) << "\""; - return; - } - - case value_t::boolean: - { - o << (m_value.boolean ? "true" : "false"); - return; - } - - case value_t::number_integer: - { - o << numtostr(m_value.number_integer).c_str(); - return; - } - - case value_t::number_unsigned: - { - o << numtostr(m_value.number_unsigned).c_str(); - return; - } - - case value_t::number_float: - { - o << numtostr(m_value.number_float).c_str(); - return; - } - - case value_t::discarded: - { - o << "<discarded>"; - return; - } - - case value_t::null: - { - o << "null"; - return; - } - } - } - - private: - ////////////////////// - // member variables // - ////////////////////// - - /// the type of the current element - value_t m_type = value_t::null; - - /// the value of the current element - json_value m_value = {}; - - - private: - /////////////// - // iterators // - /////////////// - - /*! - @brief an iterator for primitive JSON types - - This class models an iterator for primitive JSON types (boolean, number, - string). It's only purpose is to allow the iterator/const_iterator classes - to "iterate" over primitive values. Internally, the iterator is modeled by - a `difference_type` variable. Value begin_value (`0`) models the begin, - end_value (`1`) models past the end. - */ - class primitive_iterator_t - { - public: - - difference_type get_value() const noexcept - { - return m_it; - } - /// set iterator to a defined beginning - void set_begin() noexcept - { - m_it = begin_value; - } - - /// set iterator to a defined past the end - void set_end() noexcept - { - m_it = end_value; - } - - /// return whether the iterator can be dereferenced - constexpr bool is_begin() const noexcept - { - return (m_it == begin_value); - } - - /// return whether the iterator is at end - constexpr bool is_end() const noexcept - { - return (m_it == end_value); - } - - friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it == rhs.m_it; - } - - friend constexpr bool operator!=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return !(lhs == rhs); - } - - friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it < rhs.m_it; - } - - friend constexpr bool operator<=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it <= rhs.m_it; - } - - friend constexpr bool operator>(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it > rhs.m_it; - } - - friend constexpr bool operator>=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it >= rhs.m_it; - } - - primitive_iterator_t operator+(difference_type i) - { - auto result = *this; - result += i; - return result; - } - - friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it - rhs.m_it; - } - - friend std::ostream& operator<<(std::ostream& os, primitive_iterator_t it) - { - return os << it.m_it; - } - - primitive_iterator_t& operator++() - { - ++m_it; - return *this; - } - - primitive_iterator_t operator++(int) - { - auto result = *this; - m_it++; - return result; - } - - primitive_iterator_t& operator--() - { - --m_it; - return *this; - } - - primitive_iterator_t operator--(int) - { - auto result = *this; - m_it--; - return result; - } - - primitive_iterator_t& operator+=(difference_type n) - { - m_it += n; - return *this; - } - - primitive_iterator_t& operator-=(difference_type n) - { - m_it -= n; - return *this; - } - - private: - static constexpr difference_type begin_value = 0; - static constexpr difference_type end_value = begin_value + 1; - - /// iterator as signed integer type - difference_type m_it = std::numeric_limits<std::ptrdiff_t>::denorm_min(); - }; - - /*! - @brief an iterator value - - @note This structure could easily be a union, but MSVC currently does not - allow unions members with complex constructors, see - https://github.com/nlohmann/json/pull/105. - */ - struct internal_iterator - { - /// iterator for JSON objects - typename object_t::iterator object_iterator; - /// iterator for JSON arrays - typename array_t::iterator array_iterator; - /// generic iterator for all other types - primitive_iterator_t primitive_iterator; - - /// create an uninitialized internal_iterator - internal_iterator() noexcept - : object_iterator(), array_iterator(), primitive_iterator() - {} - }; - - /// proxy class for the iterator_wrapper functions - template<typename IteratorType> - class iteration_proxy - { - private: - /// helper class for iteration - class iteration_proxy_internal - { - private: - /// the iterator - IteratorType anchor; - /// an index for arrays (used to create key names) - size_t array_index = 0; - - public: - explicit iteration_proxy_internal(IteratorType it) noexcept - : anchor(it) - {} - - /// dereference operator (needed for range-based for) - iteration_proxy_internal& operator*() - { - return *this; - } - - /// increment operator (needed for range-based for) - iteration_proxy_internal& operator++() - { - ++anchor; - ++array_index; - - return *this; - } - - /// inequality operator (needed for range-based for) - bool operator!= (const iteration_proxy_internal& o) const - { - return anchor != o.anchor; - } - - /// return key of the iterator - typename basic_json::string_t key() const - { - assert(anchor.m_object != nullptr); - - switch (anchor.m_object->type()) - { - // use integer array index as key - case value_t::array: - { - return std::to_string(array_index); - } - - // use key from the object - case value_t::object: - { - return anchor.key(); - } - - // use an empty key for all primitive types - default: - { - return ""; - } - } - } - - /// return value of the iterator - typename IteratorType::reference value() const - { - return anchor.value(); - } - }; - - /// the container to iterate - typename IteratorType::reference container; - - public: - /// construct iteration proxy from a container - explicit iteration_proxy(typename IteratorType::reference cont) - : container(cont) - {} - - /// return iterator begin (needed for range-based for) - iteration_proxy_internal begin() noexcept - { - return iteration_proxy_internal(container.begin()); - } - - /// return iterator end (needed for range-based for) - iteration_proxy_internal end() noexcept - { - return iteration_proxy_internal(container.end()); - } - }; - - public: - /*! - @brief a template for a random access iterator for the @ref basic_json class - - This class implements a both iterators (iterator and const_iterator) for the - @ref basic_json class. - - @note An iterator is called *initialized* when a pointer to a JSON value - has been set (e.g., by a constructor or a copy assignment). If the - iterator is default-constructed, it is *uninitialized* and most - methods are undefined. **The library uses assertions to detect calls - on uninitialized iterators.** - - @requirement The class satisfies the following concept requirements: - - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator): - The iterator that can be moved to point (forward and backward) to any - element in constant time. - - @since version 1.0.0, simplified in version 2.0.9 - */ - template<typename U> - class iter_impl : public std::iterator<std::random_access_iterator_tag, U> - { - /// allow basic_json to access private members - friend class basic_json; - - // make sure U is basic_json or const basic_json - static_assert(std::is_same<U, basic_json>::value - or std::is_same<U, const basic_json>::value, - "iter_impl only accepts (const) basic_json"); - - public: - /// the type of the values when the iterator is dereferenced - using value_type = typename basic_json::value_type; - /// a type to represent differences between iterators - using difference_type = typename basic_json::difference_type; - /// defines a pointer to the type iterated over (value_type) - using pointer = typename std::conditional<std::is_const<U>::value, - typename basic_json::const_pointer, - typename basic_json::pointer>::type; - /// defines a reference to the type iterated over (value_type) - using reference = typename std::conditional<std::is_const<U>::value, - typename basic_json::const_reference, - typename basic_json::reference>::type; - /// the category of the iterator - using iterator_category = std::bidirectional_iterator_tag; - - /// default constructor - iter_impl() = default; - - /*! - @brief constructor for a given JSON instance - @param[in] object pointer to a JSON object for this iterator - @pre object != nullptr - @post The iterator is initialized; i.e. `m_object != nullptr`. - */ - explicit iter_impl(pointer object) noexcept - : m_object(object) - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = typename object_t::iterator(); - break; - } - - case basic_json::value_t::array: - { - m_it.array_iterator = typename array_t::iterator(); - break; - } - - default: - { - m_it.primitive_iterator = primitive_iterator_t(); - break; - } - } - } - - /* - Use operator `const_iterator` instead of `const_iterator(const iterator& - other) noexcept` to avoid two class definitions for @ref iterator and - @ref const_iterator. - - This function is only called if this class is an @ref iterator. If this - class is a @ref const_iterator this function is not called. - */ - operator const_iterator() const - { - const_iterator ret; - - if (m_object) - { - ret.m_object = m_object; - ret.m_it = m_it; - } - - return ret; - } - - /*! - @brief copy constructor - @param[in] other iterator to copy from - @note It is not checked whether @a other is initialized. - */ - iter_impl(const iter_impl& other) noexcept - : m_object(other.m_object), m_it(other.m_it) - {} - - /*! - @brief copy assignment - @param[in,out] other iterator to copy from - @note It is not checked whether @a other is initialized. - */ - iter_impl& operator=(iter_impl other) noexcept( - std::is_nothrow_move_constructible<pointer>::value and - std::is_nothrow_move_assignable<pointer>::value and - std::is_nothrow_move_constructible<internal_iterator>::value and - std::is_nothrow_move_assignable<internal_iterator>::value - ) - { - std::swap(m_object, other.m_object); - std::swap(m_it, other.m_it); - return *this; - } - - private: - /*! - @brief set the iterator to the first value - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - void set_begin() noexcept - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = m_object->m_value.object->begin(); - break; - } - - case basic_json::value_t::array: - { - m_it.array_iterator = m_object->m_value.array->begin(); - break; - } - - case basic_json::value_t::null: - { - // set to end so begin()==end() is true: null is empty - m_it.primitive_iterator.set_end(); - break; - } - - default: - { - m_it.primitive_iterator.set_begin(); - break; - } - } - } - - /*! - @brief set the iterator past the last value - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - void set_end() noexcept - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = m_object->m_value.object->end(); - break; - } - - case basic_json::value_t::array: - { - m_it.array_iterator = m_object->m_value.array->end(); - break; - } - - default: - { - m_it.primitive_iterator.set_end(); - break; - } - } - } - - public: - /*! - @brief return a reference to the value pointed to by the iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference operator*() const - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - assert(m_it.object_iterator != m_object->m_value.object->end()); - return m_it.object_iterator->second; - } - - case basic_json::value_t::array: - { - assert(m_it.array_iterator != m_object->m_value.array->end()); - return *m_it.array_iterator; - } - - case basic_json::value_t::null: - { - JSON_THROW(std::out_of_range("cannot get value")); - } - - default: - { - if (m_it.primitive_iterator.is_begin()) - { - return *m_object; - } - - JSON_THROW(std::out_of_range("cannot get value")); - } - } - } - - /*! - @brief dereference the iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - pointer operator->() const - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - assert(m_it.object_iterator != m_object->m_value.object->end()); - return &(m_it.object_iterator->second); - } - - case basic_json::value_t::array: - { - assert(m_it.array_iterator != m_object->m_value.array->end()); - return &*m_it.array_iterator; - } - - default: - { - if (m_it.primitive_iterator.is_begin()) - { - return m_object; - } - - JSON_THROW(std::out_of_range("cannot get value")); - } - } - } - - /*! - @brief post-increment (it++) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator++(int) - { - auto result = *this; - ++(*this); - return result; - } - - /*! - @brief pre-increment (++it) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator++() - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - std::advance(m_it.object_iterator, 1); - break; - } - - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, 1); - break; - } - - default: - { - ++m_it.primitive_iterator; - break; - } - } - - return *this; - } - - /*! - @brief post-decrement (it--) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator--(int) - { - auto result = *this; - --(*this); - return result; - } - - /*! - @brief pre-decrement (--it) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator--() - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - std::advance(m_it.object_iterator, -1); - break; - } - - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, -1); - break; - } - - default: - { - --m_it.primitive_iterator; - break; - } - } - - return *this; - } - - /*! - @brief comparison: equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator==(const iter_impl& other) const - { - // if objects are not the same, the comparison is undefined - if (m_object != other.m_object) - { - JSON_THROW(std::domain_error("cannot compare iterators of different containers")); - } - - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - return (m_it.object_iterator == other.m_it.object_iterator); - } - - case basic_json::value_t::array: - { - return (m_it.array_iterator == other.m_it.array_iterator); - } - - default: - { - return (m_it.primitive_iterator == other.m_it.primitive_iterator); - } - } - } - - /*! - @brief comparison: not equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator!=(const iter_impl& other) const - { - return not operator==(other); - } - - /*! - @brief comparison: smaller - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator<(const iter_impl& other) const - { - // if objects are not the same, the comparison is undefined - if (m_object != other.m_object) - { - JSON_THROW(std::domain_error("cannot compare iterators of different containers")); - } - - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(std::domain_error("cannot compare order of object iterators")); - } - - case basic_json::value_t::array: - { - return (m_it.array_iterator < other.m_it.array_iterator); - } - - default: - { - return (m_it.primitive_iterator < other.m_it.primitive_iterator); - } - } - } - - /*! - @brief comparison: less than or equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator<=(const iter_impl& other) const - { - return not other.operator < (*this); - } - - /*! - @brief comparison: greater than - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator>(const iter_impl& other) const - { - return not operator<=(other); - } - - /*! - @brief comparison: greater than or equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator>=(const iter_impl& other) const - { - return not operator<(other); - } - - /*! - @brief add to iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator+=(difference_type i) - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(std::domain_error("cannot use offsets with object iterators")); - } - - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, i); - break; - } - - default: - { - m_it.primitive_iterator += i; - break; - } - } - - return *this; - } - - /*! - @brief subtract from iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator-=(difference_type i) - { - return operator+=(-i); - } - - /*! - @brief add to iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator+(difference_type i) - { - auto result = *this; - result += i; - return result; - } - - /*! - @brief subtract from iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator-(difference_type i) - { - auto result = *this; - result -= i; - return result; - } - - /*! - @brief return difference - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - difference_type operator-(const iter_impl& other) const - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(std::domain_error("cannot use offsets with object iterators")); - } - - case basic_json::value_t::array: - { - return m_it.array_iterator - other.m_it.array_iterator; - } - - default: - { - return m_it.primitive_iterator - other.m_it.primitive_iterator; - } - } - } - - /*! - @brief access to successor - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference operator[](difference_type n) const - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(std::domain_error("cannot use operator[] for object iterators")); - } - - case basic_json::value_t::array: - { - return *std::next(m_it.array_iterator, n); - } - - case basic_json::value_t::null: - { - JSON_THROW(std::out_of_range("cannot get value")); - } - - default: - { - if (m_it.primitive_iterator.get_value() == -n) - { - return *m_object; - } - - JSON_THROW(std::out_of_range("cannot get value")); - } - } - } - - /*! - @brief return the key of an object iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - typename object_t::key_type key() const - { - assert(m_object != nullptr); - - if (m_object->is_object()) - { - return m_it.object_iterator->first; - } - - JSON_THROW(std::domain_error("cannot use key() for non-object iterators")); - } - - /*! - @brief return the value of an iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference value() const - { - return operator*(); - } - - private: - /// associated JSON instance - pointer m_object = nullptr; - /// the actual iterator of the associated instance - internal_iterator m_it = internal_iterator(); - }; - - /*! - @brief a template for a reverse iterator class - - @tparam Base the base iterator type to reverse. Valid types are @ref - iterator (to create @ref reverse_iterator) and @ref const_iterator (to - create @ref const_reverse_iterator). - - @requirement The class satisfies the following concept requirements: - - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator): - The iterator that can be moved to point (forward and backward) to any - element in constant time. - - [OutputIterator](http://en.cppreference.com/w/cpp/concept/OutputIterator): - It is possible to write to the pointed-to element (only if @a Base is - @ref iterator). - - @since version 1.0.0 - */ - template<typename Base> - class json_reverse_iterator : public std::reverse_iterator<Base> - { - public: - /// shortcut to the reverse iterator adaptor - using base_iterator = std::reverse_iterator<Base>; - /// the reference type for the pointed-to element - using reference = typename Base::reference; - - /// create reverse iterator from iterator - json_reverse_iterator(const typename base_iterator::iterator_type& it) noexcept - : base_iterator(it) - {} - - /// create reverse iterator from base class - json_reverse_iterator(const base_iterator& it) noexcept - : base_iterator(it) - {} - - /// post-increment (it++) - json_reverse_iterator operator++(int) - { - return base_iterator::operator++(1); - } - - /// pre-increment (++it) - json_reverse_iterator& operator++() - { - base_iterator::operator++(); - return *this; - } - - /// post-decrement (it--) - json_reverse_iterator operator--(int) - { - return base_iterator::operator--(1); - } - - /// pre-decrement (--it) - json_reverse_iterator& operator--() - { - base_iterator::operator--(); - return *this; - } - - /// add to iterator - json_reverse_iterator& operator+=(difference_type i) - { - base_iterator::operator+=(i); - return *this; - } - - /// add to iterator - json_reverse_iterator operator+(difference_type i) const - { - auto result = *this; - result += i; - return result; - } - - /// subtract from iterator - json_reverse_iterator operator-(difference_type i) const - { - auto result = *this; - result -= i; - return result; - } - - /// return difference - difference_type operator-(const json_reverse_iterator& other) const - { - return this->base() - other.base(); - } - - /// access to successor - reference operator[](difference_type n) const - { - return *(this->operator+(n)); - } - - /// return the key of an object iterator - typename object_t::key_type key() const - { - auto it = --this->base(); - return it.key(); - } - - /// return the value of an iterator - reference value() const - { - auto it = --this->base(); - return it.operator * (); - } - }; - - - private: - ////////////////////// - // lexer and parser // - ////////////////////// - - /*! - @brief lexical analysis - - This class organizes the lexical analysis during JSON deserialization. The - core of it is a scanner generated by [re2c](http://re2c.org) that - processes a buffer and recognizes tokens according to RFC 7159. - */ - class lexer - { - public: - /// token types for the parser - enum class token_type - { - uninitialized, ///< indicating the scanner is uninitialized - literal_true, ///< the `true` literal - literal_false, ///< the `false` literal - literal_null, ///< the `null` literal - value_string, ///< a string -- use get_string() for actual value - value_unsigned, ///< an unsigned integer -- use get_number() for actual value - value_integer, ///< a signed integer -- use get_number() for actual value - value_float, ///< an floating point number -- use get_number() for actual value - begin_array, ///< the character for array begin `[` - begin_object, ///< the character for object begin `{` - end_array, ///< the character for array end `]` - end_object, ///< the character for object end `}` - name_separator, ///< the name separator `:` - value_separator, ///< the value separator `,` - parse_error, ///< indicating a parse error - end_of_input ///< indicating the end of the input buffer - }; - - /// the char type to use in the lexer - using lexer_char_t = unsigned char; - - /// a lexer from a buffer with given length - lexer(const lexer_char_t* buff, const size_t len) noexcept - : m_content(buff) - { - assert(m_content != nullptr); - m_start = m_cursor = m_content; - m_limit = m_content + len; - } - - /// a lexer from an input stream - explicit lexer(std::istream& s) - : m_stream(&s), m_line_buffer() - { - // immediately abort if stream is erroneous - if (s.fail()) - { - JSON_THROW(std::invalid_argument("stream error")); - } - - // fill buffer - fill_line_buffer(); - - // skip UTF-8 byte-order mark - if (m_line_buffer.size() >= 3 and m_line_buffer.substr(0, 3) == "\xEF\xBB\xBF") - { - m_line_buffer[0] = ' '; - m_line_buffer[1] = ' '; - m_line_buffer[2] = ' '; - } - } - - // switch off unwanted functions (due to pointer members) - lexer() = delete; - lexer(const lexer&) = delete; - lexer operator=(const lexer&) = delete; - - /*! - @brief create a string from one or two Unicode code points - - There are two cases: (1) @a codepoint1 is in the Basic Multilingual - Plane (U+0000 through U+FFFF) and @a codepoint2 is 0, or (2) - @a codepoint1 and @a codepoint2 are a UTF-16 surrogate pair to - represent a code point above U+FFFF. - - @param[in] codepoint1 the code point (can be high surrogate) - @param[in] codepoint2 the code point (can be low surrogate or 0) - - @return string representation of the code point; the length of the - result string is between 1 and 4 characters. - - @throw std::out_of_range if code point is > 0x10ffff; example: `"code - points above 0x10FFFF are invalid"` - @throw std::invalid_argument if the low surrogate is invalid; example: - `""missing or wrong low surrogate""` - - @complexity Constant. - - @see <http://en.wikipedia.org/wiki/UTF-8#Sample_code> - */ - static string_t to_unicode(const std::size_t codepoint1, - const std::size_t codepoint2 = 0) - { - // calculate the code point from the given code points - std::size_t codepoint = codepoint1; - - // check if codepoint1 is a high surrogate - if (codepoint1 >= 0xD800 and codepoint1 <= 0xDBFF) - { - // check if codepoint2 is a low surrogate - if (codepoint2 >= 0xDC00 and codepoint2 <= 0xDFFF) - { - codepoint = - // high surrogate occupies the most significant 22 bits - (codepoint1 << 10) - // low surrogate occupies the least significant 15 bits - + codepoint2 - // there is still the 0xD800, 0xDC00 and 0x10000 noise - // in the result so we have to subtract with: - // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00 - - 0x35FDC00; - } - else - { - JSON_THROW(std::invalid_argument("missing or wrong low surrogate")); - } - } - - string_t result; - - if (codepoint < 0x80) - { - // 1-byte characters: 0xxxxxxx (ASCII) - result.append(1, static_cast<typename string_t::value_type>(codepoint)); - } - else if (codepoint <= 0x7ff) - { - // 2-byte characters: 110xxxxx 10xxxxxx - result.append(1, static_cast<typename string_t::value_type>(0xC0 | ((codepoint >> 6) & 0x1F))); - result.append(1, static_cast<typename string_t::value_type>(0x80 | (codepoint & 0x3F))); - } - else if (codepoint <= 0xffff) - { - // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx - result.append(1, static_cast<typename string_t::value_type>(0xE0 | ((codepoint >> 12) & 0x0F))); - result.append(1, static_cast<typename string_t::value_type>(0x80 | ((codepoint >> 6) & 0x3F))); - result.append(1, static_cast<typename string_t::value_type>(0x80 | (codepoint & 0x3F))); - } - else if (codepoint <= 0x10ffff) - { - // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx - result.append(1, static_cast<typename string_t::value_type>(0xF0 | ((codepoint >> 18) & 0x07))); - result.append(1, static_cast<typename string_t::value_type>(0x80 | ((codepoint >> 12) & 0x3F))); - result.append(1, static_cast<typename string_t::value_type>(0x80 | ((codepoint >> 6) & 0x3F))); - result.append(1, static_cast<typename string_t::value_type>(0x80 | (codepoint & 0x3F))); - } - else - { - JSON_THROW(std::out_of_range("code points above 0x10FFFF are invalid")); - } - - return result; - } - - /// return name of values of type token_type (only used for errors) - static std::string token_type_name(const token_type t) - { - switch (t) - { - case token_type::uninitialized: - return "<uninitialized>"; - case token_type::literal_true: - return "true literal"; - case token_type::literal_false: - return "false literal"; - case token_type::literal_null: - return "null literal"; - case token_type::value_string: - return "string literal"; - case lexer::token_type::value_unsigned: - case lexer::token_type::value_integer: - case lexer::token_type::value_float: - return "number literal"; - case token_type::begin_array: - return "'['"; - case token_type::begin_object: - return "'{'"; - case token_type::end_array: - return "']'"; - case token_type::end_object: - return "'}'"; - case token_type::name_separator: - return "':'"; - case token_type::value_separator: - return "','"; - case token_type::parse_error: - return "<parse error>"; - case token_type::end_of_input: - return "end of input"; - default: - { - // catch non-enum values - return "unknown token"; // LCOV_EXCL_LINE - } - } - } - - /*! - This function implements a scanner for JSON. It is specified using - regular expressions that try to follow RFC 7159 as close as possible. - These regular expressions are then translated into a minimized - deterministic finite automaton (DFA) by the tool - [re2c](http://re2c.org). As a result, the translated code for this - function consists of a large block of code with `goto` jumps. - - @return the class of the next token read from the buffer - - @complexity Linear in the length of the input.\n - - Proposition: The loop below will always terminate for finite input.\n - - Proof (by contradiction): Assume a finite input. To loop forever, the - loop must never hit code with a `break` statement. The only code - snippets without a `break` statement are the continue statements for - whitespace and byte-order-marks. To loop forever, the input must be an - infinite sequence of whitespace or byte-order-marks. This contradicts - the assumption of finite input, q.e.d. - */ - token_type scan() - { - while (true) - { - // pointer for backtracking information - m_marker = nullptr; - - // remember the begin of the token - m_start = m_cursor; - assert(m_start != nullptr); - - - { - lexer_char_t yych; - unsigned int yyaccept = 0; - static const unsigned char yybm[] = - { - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 32, 32, 0, 0, 32, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 160, 128, 0, 128, 128, 128, 128, 128, - 128, 128, 128, 128, 128, 128, 128, 128, - 192, 192, 192, 192, 192, 192, 192, 192, - 192, 192, 128, 128, 128, 128, 128, 128, - 128, 128, 128, 128, 128, 128, 128, 128, - 128, 128, 128, 128, 128, 128, 128, 128, - 128, 128, 128, 128, 128, 128, 128, 128, - 128, 128, 128, 128, 0, 128, 128, 128, - 128, 128, 128, 128, 128, 128, 128, 128, - 128, 128, 128, 128, 128, 128, 128, 128, - 128, 128, 128, 128, 128, 128, 128, 128, - 128, 128, 128, 128, 128, 128, 128, 128, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - }; - if ((m_limit - m_cursor) < 5) - { - fill_line_buffer(5); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yybm[0 + yych] & 32) - { - goto basic_json_parser_6; - } - if (yych <= '[') - { - if (yych <= '-') - { - if (yych <= '"') - { - if (yych <= 0x00) - { - goto basic_json_parser_2; - } - if (yych <= '!') - { - goto basic_json_parser_4; - } - goto basic_json_parser_9; - } - else - { - if (yych <= '+') - { - goto basic_json_parser_4; - } - if (yych <= ',') - { - goto basic_json_parser_10; - } - goto basic_json_parser_12; - } - } - else - { - if (yych <= '9') - { - if (yych <= '/') - { - goto basic_json_parser_4; - } - if (yych <= '0') - { - goto basic_json_parser_13; - } - goto basic_json_parser_15; - } - else - { - if (yych <= ':') - { - goto basic_json_parser_17; - } - if (yych <= 'Z') - { - goto basic_json_parser_4; - } - goto basic_json_parser_19; - } - } - } - else - { - if (yych <= 'n') - { - if (yych <= 'e') - { - if (yych == ']') - { - goto basic_json_parser_21; - } - goto basic_json_parser_4; - } - else - { - if (yych <= 'f') - { - goto basic_json_parser_23; - } - if (yych <= 'm') - { - goto basic_json_parser_4; - } - goto basic_json_parser_24; - } - } - else - { - if (yych <= 'z') - { - if (yych == 't') - { - goto basic_json_parser_25; - } - goto basic_json_parser_4; - } - else - { - if (yych <= '{') - { - goto basic_json_parser_26; - } - if (yych == '}') - { - goto basic_json_parser_28; - } - goto basic_json_parser_4; - } - } - } -basic_json_parser_2: - ++m_cursor; - { - last_token_type = token_type::end_of_input; - break; - } -basic_json_parser_4: - ++m_cursor; -basic_json_parser_5: - { - last_token_type = token_type::parse_error; - break; - } -basic_json_parser_6: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yybm[0 + yych] & 32) - { - goto basic_json_parser_6; - } - { - continue; - } -basic_json_parser_9: - yyaccept = 0; - yych = *(m_marker = ++m_cursor); - if (yych <= 0x1F) - { - goto basic_json_parser_5; - } - if (yych <= 0x7F) - { - goto basic_json_parser_31; - } - if (yych <= 0xC1) - { - goto basic_json_parser_5; - } - if (yych <= 0xF4) - { - goto basic_json_parser_31; - } - goto basic_json_parser_5; -basic_json_parser_10: - ++m_cursor; - { - last_token_type = token_type::value_separator; - break; - } -basic_json_parser_12: - yych = *++m_cursor; - if (yych <= '/') - { - goto basic_json_parser_5; - } - if (yych <= '0') - { - goto basic_json_parser_43; - } - if (yych <= '9') - { - goto basic_json_parser_45; - } - goto basic_json_parser_5; -basic_json_parser_13: - yyaccept = 1; - yych = *(m_marker = ++m_cursor); - if (yych <= '9') - { - if (yych == '.') - { - goto basic_json_parser_47; - } - if (yych >= '0') - { - goto basic_json_parser_48; - } - } - else - { - if (yych <= 'E') - { - if (yych >= 'E') - { - goto basic_json_parser_51; - } - } - else - { - if (yych == 'e') - { - goto basic_json_parser_51; - } - } - } -basic_json_parser_14: - { - last_token_type = token_type::value_unsigned; - break; - } -basic_json_parser_15: - yyaccept = 1; - m_marker = ++m_cursor; - if ((m_limit - m_cursor) < 3) - { - fill_line_buffer(3); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yybm[0 + yych] & 64) - { - goto basic_json_parser_15; - } - if (yych <= 'D') - { - if (yych == '.') - { - goto basic_json_parser_47; - } - goto basic_json_parser_14; - } - else - { - if (yych <= 'E') - { - goto basic_json_parser_51; - } - if (yych == 'e') - { - goto basic_json_parser_51; - } - goto basic_json_parser_14; - } -basic_json_parser_17: - ++m_cursor; - { - last_token_type = token_type::name_separator; - break; - } -basic_json_parser_19: - ++m_cursor; - { - last_token_type = token_type::begin_array; - break; - } -basic_json_parser_21: - ++m_cursor; - { - last_token_type = token_type::end_array; - break; - } -basic_json_parser_23: - yyaccept = 0; - yych = *(m_marker = ++m_cursor); - if (yych == 'a') - { - goto basic_json_parser_52; - } - goto basic_json_parser_5; -basic_json_parser_24: - yyaccept = 0; - yych = *(m_marker = ++m_cursor); - if (yych == 'u') - { - goto basic_json_parser_53; - } - goto basic_json_parser_5; -basic_json_parser_25: - yyaccept = 0; - yych = *(m_marker = ++m_cursor); - if (yych == 'r') - { - goto basic_json_parser_54; - } - goto basic_json_parser_5; -basic_json_parser_26: - ++m_cursor; - { - last_token_type = token_type::begin_object; - break; - } -basic_json_parser_28: - ++m_cursor; - { - last_token_type = token_type::end_object; - break; - } -basic_json_parser_30: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; -basic_json_parser_31: - if (yybm[0 + yych] & 128) - { - goto basic_json_parser_30; - } - if (yych <= 0xE0) - { - if (yych <= '\\') - { - if (yych <= 0x1F) - { - goto basic_json_parser_32; - } - if (yych <= '"') - { - goto basic_json_parser_33; - } - goto basic_json_parser_35; - } - else - { - if (yych <= 0xC1) - { - goto basic_json_parser_32; - } - if (yych <= 0xDF) - { - goto basic_json_parser_36; - } - goto basic_json_parser_37; - } - } - else - { - if (yych <= 0xEF) - { - if (yych == 0xED) - { - goto basic_json_parser_39; - } - goto basic_json_parser_38; - } - else - { - if (yych <= 0xF0) - { - goto basic_json_parser_40; - } - if (yych <= 0xF3) - { - goto basic_json_parser_41; - } - if (yych <= 0xF4) - { - goto basic_json_parser_42; - } - } - } -basic_json_parser_32: - m_cursor = m_marker; - if (yyaccept <= 1) - { - if (yyaccept == 0) - { - goto basic_json_parser_5; - } - else - { - goto basic_json_parser_14; - } - } - else - { - if (yyaccept == 2) - { - goto basic_json_parser_44; - } - else - { - goto basic_json_parser_58; - } - } -basic_json_parser_33: - ++m_cursor; - { - last_token_type = token_type::value_string; - break; - } -basic_json_parser_35: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= 'e') - { - if (yych <= '/') - { - if (yych == '"') - { - goto basic_json_parser_30; - } - if (yych <= '.') - { - goto basic_json_parser_32; - } - goto basic_json_parser_30; - } - else - { - if (yych <= '\\') - { - if (yych <= '[') - { - goto basic_json_parser_32; - } - goto basic_json_parser_30; - } - else - { - if (yych == 'b') - { - goto basic_json_parser_30; - } - goto basic_json_parser_32; - } - } - } - else - { - if (yych <= 'q') - { - if (yych <= 'f') - { - goto basic_json_parser_30; - } - if (yych == 'n') - { - goto basic_json_parser_30; - } - goto basic_json_parser_32; - } - else - { - if (yych <= 's') - { - if (yych <= 'r') - { - goto basic_json_parser_30; - } - goto basic_json_parser_32; - } - else - { - if (yych <= 't') - { - goto basic_json_parser_30; - } - if (yych <= 'u') - { - goto basic_json_parser_55; - } - goto basic_json_parser_32; - } - } - } -basic_json_parser_36: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= 0x7F) - { - goto basic_json_parser_32; - } - if (yych <= 0xBF) - { - goto basic_json_parser_30; - } - goto basic_json_parser_32; -basic_json_parser_37: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= 0x9F) - { - goto basic_json_parser_32; - } - if (yych <= 0xBF) - { - goto basic_json_parser_36; - } - goto basic_json_parser_32; -basic_json_parser_38: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= 0x7F) - { - goto basic_json_parser_32; - } - if (yych <= 0xBF) - { - goto basic_json_parser_36; - } - goto basic_json_parser_32; -basic_json_parser_39: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= 0x7F) - { - goto basic_json_parser_32; - } - if (yych <= 0x9F) - { - goto basic_json_parser_36; - } - goto basic_json_parser_32; -basic_json_parser_40: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= 0x8F) - { - goto basic_json_parser_32; - } - if (yych <= 0xBF) - { - goto basic_json_parser_38; - } - goto basic_json_parser_32; -basic_json_parser_41: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= 0x7F) - { - goto basic_json_parser_32; - } - if (yych <= 0xBF) - { - goto basic_json_parser_38; - } - goto basic_json_parser_32; -basic_json_parser_42: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= 0x7F) - { - goto basic_json_parser_32; - } - if (yych <= 0x8F) - { - goto basic_json_parser_38; - } - goto basic_json_parser_32; -basic_json_parser_43: - yyaccept = 2; - yych = *(m_marker = ++m_cursor); - if (yych <= '9') - { - if (yych == '.') - { - goto basic_json_parser_47; - } - if (yych >= '0') - { - goto basic_json_parser_48; - } - } - else - { - if (yych <= 'E') - { - if (yych >= 'E') - { - goto basic_json_parser_51; - } - } - else - { - if (yych == 'e') - { - goto basic_json_parser_51; - } - } - } -basic_json_parser_44: - { - last_token_type = token_type::value_integer; - break; - } -basic_json_parser_45: - yyaccept = 2; - m_marker = ++m_cursor; - if ((m_limit - m_cursor) < 3) - { - fill_line_buffer(3); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= '9') - { - if (yych == '.') - { - goto basic_json_parser_47; - } - if (yych <= '/') - { - goto basic_json_parser_44; - } - goto basic_json_parser_45; - } - else - { - if (yych <= 'E') - { - if (yych <= 'D') - { - goto basic_json_parser_44; - } - goto basic_json_parser_51; - } - else - { - if (yych == 'e') - { - goto basic_json_parser_51; - } - goto basic_json_parser_44; - } - } -basic_json_parser_47: - yych = *++m_cursor; - if (yych <= '/') - { - goto basic_json_parser_32; - } - if (yych <= '9') - { - goto basic_json_parser_56; - } - goto basic_json_parser_32; -basic_json_parser_48: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= '/') - { - goto basic_json_parser_50; - } - if (yych <= '9') - { - goto basic_json_parser_48; - } -basic_json_parser_50: - { - last_token_type = token_type::parse_error; - break; - } -basic_json_parser_51: - yych = *++m_cursor; - if (yych <= ',') - { - if (yych == '+') - { - goto basic_json_parser_59; - } - goto basic_json_parser_32; - } - else - { - if (yych <= '-') - { - goto basic_json_parser_59; - } - if (yych <= '/') - { - goto basic_json_parser_32; - } - if (yych <= '9') - { - goto basic_json_parser_60; - } - goto basic_json_parser_32; - } -basic_json_parser_52: - yych = *++m_cursor; - if (yych == 'l') - { - goto basic_json_parser_62; - } - goto basic_json_parser_32; -basic_json_parser_53: - yych = *++m_cursor; - if (yych == 'l') - { - goto basic_json_parser_63; - } - goto basic_json_parser_32; -basic_json_parser_54: - yych = *++m_cursor; - if (yych == 'u') - { - goto basic_json_parser_64; - } - goto basic_json_parser_32; -basic_json_parser_55: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= '@') - { - if (yych <= '/') - { - goto basic_json_parser_32; - } - if (yych <= '9') - { - goto basic_json_parser_65; - } - goto basic_json_parser_32; - } - else - { - if (yych <= 'F') - { - goto basic_json_parser_65; - } - if (yych <= '`') - { - goto basic_json_parser_32; - } - if (yych <= 'f') - { - goto basic_json_parser_65; - } - goto basic_json_parser_32; - } -basic_json_parser_56: - yyaccept = 3; - m_marker = ++m_cursor; - if ((m_limit - m_cursor) < 3) - { - fill_line_buffer(3); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= 'D') - { - if (yych <= '/') - { - goto basic_json_parser_58; - } - if (yych <= '9') - { - goto basic_json_parser_56; - } - } - else - { - if (yych <= 'E') - { - goto basic_json_parser_51; - } - if (yych == 'e') - { - goto basic_json_parser_51; - } - } -basic_json_parser_58: - { - last_token_type = token_type::value_float; - break; - } -basic_json_parser_59: - yych = *++m_cursor; - if (yych <= '/') - { - goto basic_json_parser_32; - } - if (yych >= ':') - { - goto basic_json_parser_32; - } -basic_json_parser_60: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= '/') - { - goto basic_json_parser_58; - } - if (yych <= '9') - { - goto basic_json_parser_60; - } - goto basic_json_parser_58; -basic_json_parser_62: - yych = *++m_cursor; - if (yych == 's') - { - goto basic_json_parser_66; - } - goto basic_json_parser_32; -basic_json_parser_63: - yych = *++m_cursor; - if (yych == 'l') - { - goto basic_json_parser_67; - } - goto basic_json_parser_32; -basic_json_parser_64: - yych = *++m_cursor; - if (yych == 'e') - { - goto basic_json_parser_69; - } - goto basic_json_parser_32; -basic_json_parser_65: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= '@') - { - if (yych <= '/') - { - goto basic_json_parser_32; - } - if (yych <= '9') - { - goto basic_json_parser_71; - } - goto basic_json_parser_32; - } - else - { - if (yych <= 'F') - { - goto basic_json_parser_71; - } - if (yych <= '`') - { - goto basic_json_parser_32; - } - if (yych <= 'f') - { - goto basic_json_parser_71; - } - goto basic_json_parser_32; - } -basic_json_parser_66: - yych = *++m_cursor; - if (yych == 'e') - { - goto basic_json_parser_72; - } - goto basic_json_parser_32; -basic_json_parser_67: - ++m_cursor; - { - last_token_type = token_type::literal_null; - break; - } -basic_json_parser_69: - ++m_cursor; - { - last_token_type = token_type::literal_true; - break; - } -basic_json_parser_71: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= '@') - { - if (yych <= '/') - { - goto basic_json_parser_32; - } - if (yych <= '9') - { - goto basic_json_parser_74; - } - goto basic_json_parser_32; - } - else - { - if (yych <= 'F') - { - goto basic_json_parser_74; - } - if (yych <= '`') - { - goto basic_json_parser_32; - } - if (yych <= 'f') - { - goto basic_json_parser_74; - } - goto basic_json_parser_32; - } -basic_json_parser_72: - ++m_cursor; - { - last_token_type = token_type::literal_false; - break; - } -basic_json_parser_74: - ++m_cursor; - if (m_limit <= m_cursor) - { - fill_line_buffer(1); // LCOV_EXCL_LINE - } - yych = *m_cursor; - if (yych <= '@') - { - if (yych <= '/') - { - goto basic_json_parser_32; - } - if (yych <= '9') - { - goto basic_json_parser_30; - } - goto basic_json_parser_32; - } - else - { - if (yych <= 'F') - { - goto basic_json_parser_30; - } - if (yych <= '`') - { - goto basic_json_parser_32; - } - if (yych <= 'f') - { - goto basic_json_parser_30; - } - goto basic_json_parser_32; - } - } - - } - - return last_token_type; - } - - /*! - @brief append data from the stream to the line buffer - - This function is called by the scan() function when the end of the - buffer (`m_limit`) is reached and the `m_cursor` pointer cannot be - incremented without leaving the limits of the line buffer. Note re2c - decides when to call this function. - - If the lexer reads from contiguous storage, there is no trailing null - byte. Therefore, this function must make sure to add these padding - null bytes. - - If the lexer reads from an input stream, this function reads the next - line of the input. - - @pre - p p p p p p u u u u u x . . . . . . - ^ ^ ^ ^ - m_content m_start | m_limit - m_cursor - - @post - u u u u u x x x x x x x . . . . . . - ^ ^ ^ - | m_cursor m_limit - m_start - m_content - */ - void fill_line_buffer(size_t n = 0) - { - // if line buffer is used, m_content points to its data - assert(m_line_buffer.empty() - or m_content == reinterpret_cast<const lexer_char_t*>(m_line_buffer.data())); - - // if line buffer is used, m_limit is set past the end of its data - assert(m_line_buffer.empty() - or m_limit == m_content + m_line_buffer.size()); - - // pointer relationships - assert(m_content <= m_start); - assert(m_start <= m_cursor); - assert(m_cursor <= m_limit); - assert(m_marker == nullptr or m_marker <= m_limit); - - // number of processed characters (p) - const auto num_processed_chars = static_cast<size_t>(m_start - m_content); - // offset for m_marker wrt. to m_start - const auto offset_marker = (m_marker == nullptr) ? 0 : m_marker - m_start; - // number of unprocessed characters (u) - const auto offset_cursor = m_cursor - m_start; - - // no stream is used or end of file is reached - if (m_stream == nullptr or m_stream->eof()) - { - // m_start may or may not be pointing into m_line_buffer at - // this point. We trust the standard library to do the right - // thing. See http://stackoverflow.com/q/28142011/266378 - m_line_buffer.assign(m_start, m_limit); - - // append n characters to make sure that there is sufficient - // space between m_cursor and m_limit - m_line_buffer.append(1, '\x00'); - if (n > 0) - { - m_line_buffer.append(n - 1, '\x01'); - } - } - else - { - // delete processed characters from line buffer - m_line_buffer.erase(0, num_processed_chars); - // read next line from input stream - m_line_buffer_tmp.clear(); - std::getline(*m_stream, m_line_buffer_tmp, '\n'); - - // add line with newline symbol to the line buffer - m_line_buffer += m_line_buffer_tmp; - m_line_buffer.push_back('\n'); - } - - // set pointers - m_content = reinterpret_cast<const lexer_char_t*>(m_line_buffer.data()); - assert(m_content != nullptr); - m_start = m_content; - m_marker = m_start + offset_marker; - m_cursor = m_start + offset_cursor; - m_limit = m_start + m_line_buffer.size(); - } - - /// return string representation of last read token - string_t get_token_string() const - { - assert(m_start != nullptr); - return string_t(reinterpret_cast<typename string_t::const_pointer>(m_start), - static_cast<size_t>(m_cursor - m_start)); - } - - /*! - @brief return string value for string tokens - - The function iterates the characters between the opening and closing - quotes of the string value. The complete string is the range - [m_start,m_cursor). Consequently, we iterate from m_start+1 to - m_cursor-1. - - We differentiate two cases: - - 1. Escaped characters. In this case, a new character is constructed - according to the nature of the escape. Some escapes create new - characters (e.g., `"\\n"` is replaced by `"\n"`), some are copied - as is (e.g., `"\\\\"`). Furthermore, Unicode escapes of the shape - `"\\uxxxx"` need special care. In this case, to_unicode takes care - of the construction of the values. - 2. Unescaped characters are copied as is. - - @pre `m_cursor - m_start >= 2`, meaning the length of the last token - is at least 2 bytes which is trivially true for any string (which - consists of at least two quotes). - - " c1 c2 c3 ... " - ^ ^ - m_start m_cursor - - @complexity Linear in the length of the string.\n - - Lemma: The loop body will always terminate.\n - - Proof (by contradiction): Assume the loop body does not terminate. As - the loop body does not contain another loop, one of the called - functions must never return. The called functions are `std::strtoul` - and to_unicode. Neither function can loop forever, so the loop body - will never loop forever which contradicts the assumption that the loop - body does not terminate, q.e.d.\n - - Lemma: The loop condition for the for loop is eventually false.\n - - Proof (by contradiction): Assume the loop does not terminate. Due to - the above lemma, this can only be due to a tautological loop - condition; that is, the loop condition i < m_cursor - 1 must always be - true. Let x be the change of i for any loop iteration. Then - m_start + 1 + x < m_cursor - 1 must hold to loop indefinitely. This - can be rephrased to m_cursor - m_start - 2 > x. With the - precondition, we x <= 0, meaning that the loop condition holds - indefinitely if i is always decreased. However, observe that the value - of i is strictly increasing with each iteration, as it is incremented - by 1 in the iteration expression and never decremented inside the loop - body. Hence, the loop condition will eventually be false which - contradicts the assumption that the loop condition is a tautology, - q.e.d. - - @return string value of current token without opening and closing - quotes - @throw std::out_of_range if to_unicode fails - */ - string_t get_string() const - { - assert(m_cursor - m_start >= 2); - - string_t result; - result.reserve(static_cast<size_t>(m_cursor - m_start - 2)); - - // iterate the result between the quotes - for (const lexer_char_t* i = m_start + 1; i < m_cursor - 1; ++i) - { - // find next escape character - auto e = std::find(i, m_cursor - 1, '\\'); - if (e != i) - { - // see https://github.com/nlohmann/json/issues/365#issuecomment-262874705 - for (auto k = i; k < e; k++) - { - result.push_back(static_cast<typename string_t::value_type>(*k)); - } - i = e - 1; // -1 because of ++i - } - else - { - // processing escaped character - // read next character - ++i; - - switch (*i) - { - // the default escapes - case 't': - { - result += "\t"; - break; - } - case 'b': - { - result += "\b"; - break; - } - case 'f': - { - result += "\f"; - break; - } - case 'n': - { - result += "\n"; - break; - } - case 'r': - { - result += "\r"; - break; - } - case '\\': - { - result += "\\"; - break; - } - case '/': - { - result += "/"; - break; - } - case '"': - { - result += "\""; - break; - } - - // unicode - case 'u': - { - // get code xxxx from uxxxx - auto codepoint = std::strtoul(std::string(reinterpret_cast<typename string_t::const_pointer>(i + 1), - 4).c_str(), nullptr, 16); - - // check if codepoint is a high surrogate - if (codepoint >= 0xD800 and codepoint <= 0xDBFF) - { - // make sure there is a subsequent unicode - if ((i + 6 >= m_limit) or * (i + 5) != '\\' or * (i + 6) != 'u') - { - JSON_THROW(std::invalid_argument("missing low surrogate")); - } - - // get code yyyy from uxxxx\uyyyy - auto codepoint2 = std::strtoul(std::string(reinterpret_cast<typename string_t::const_pointer> - (i + 7), 4).c_str(), nullptr, 16); - result += to_unicode(codepoint, codepoint2); - // skip the next 10 characters (xxxx\uyyyy) - i += 10; - } - else if (codepoint >= 0xDC00 and codepoint <= 0xDFFF) - { - // we found a lone low surrogate - JSON_THROW(std::invalid_argument("missing high surrogate")); - } - else - { - // add unicode character(s) - result += to_unicode(codepoint); - // skip the next four characters (xxxx) - i += 4; - } - break; - } - } - } - } - - return result; - } - - - /*! - @brief parse string into a built-in arithmetic type as if the current - locale is POSIX. - - @note in floating-point case strtod may parse past the token's end - - this is not an error - - @note any leading blanks are not handled - */ - struct strtonum - { - public: - strtonum(const char* start, const char* end) - : m_start(start), m_end(end) - {} - - /*! - @return true iff parsed successfully as number of type T - - @param[in,out] val shall contain parsed value, or undefined value - if could not parse - */ - template<typename T, typename = typename std::enable_if<std::is_arithmetic<T>::value>::type> - bool to(T& val) const - { - return parse(val, std::is_integral<T>()); - } - - private: - const char* const m_start = nullptr; - const char* const m_end = nullptr; - - // floating-point conversion - - // overloaded wrappers for strtod/strtof/strtold - // that will be called from parse<floating_point_t> - static void strtof(float& f, const char* str, char** endptr) - { - f = std::strtof(str, endptr); - } - - static void strtof(double& f, const char* str, char** endptr) - { - f = std::strtod(str, endptr); - } - - static void strtof(long double& f, const char* str, char** endptr) - { - f = std::strtold(str, endptr); - } - - template<typename T> - bool parse(T& value, /*is_integral=*/std::false_type) const - { - // replace decimal separator with locale-specific version, - // when necessary; data will point to either the original - // string, or buf, or tempstr containing the fixed string. - std::string tempstr; - std::array<char, 64> buf; - const size_t len = static_cast<size_t>(m_end - m_start); - - // lexer will reject empty numbers - assert(len > 0); - - // since dealing with strtod family of functions, we're - // getting the decimal point char from the C locale facilities - // instead of C++'s numpunct facet of the current std::locale - const auto loc = localeconv(); - assert(loc != nullptr); - const char decimal_point_char = (loc->decimal_point == nullptr) ? '.' : loc->decimal_point[0]; - - const char* data = m_start; - - if (decimal_point_char != '.') - { - const size_t ds_pos = static_cast<size_t>(std::find(m_start, m_end, '.') - m_start); - - if (ds_pos != len) - { - // copy the data into the local buffer or tempstr, if - // buffer is too small; replace decimal separator, and - // update data to point to the modified bytes - if ((len + 1) < buf.size()) - { - std::copy(m_start, m_end, buf.begin()); - buf[len] = 0; - buf[ds_pos] = decimal_point_char; - data = buf.data(); - } - else - { - tempstr.assign(m_start, m_end); - tempstr[ds_pos] = decimal_point_char; - data = tempstr.c_str(); - } - } - } - - char* endptr = nullptr; - value = 0; - // this calls appropriate overload depending on T - strtof(value, data, &endptr); - - // parsing was successful iff strtof parsed exactly the number - // of characters determined by the lexer (len) - const bool ok = (endptr == (data + len)); - - if (ok and (value == static_cast<T>(0.0)) and (*data == '-')) - { - // some implementations forget to negate the zero - value = -0.0; - } - - return ok; - } - - // integral conversion - - signed long long parse_integral(char** endptr, /*is_signed*/std::true_type) const - { - return std::strtoll(m_start, endptr, 10); - } - - unsigned long long parse_integral(char** endptr, /*is_signed*/std::false_type) const - { - return std::strtoull(m_start, endptr, 10); - } - - template<typename T> - bool parse(T& value, /*is_integral=*/std::true_type) const - { - char* endptr = nullptr; - errno = 0; // these are thread-local - const auto x = parse_integral(&endptr, std::is_signed<T>()); - - // called right overload? - static_assert(std::is_signed<T>() == std::is_signed<decltype(x)>(), ""); - - value = static_cast<T>(x); - - return (x == static_cast<decltype(x)>(value)) // x fits into destination T - and (x < 0) == (value < 0) // preserved sign - //and ((x != 0) or is_integral()) // strto[u]ll did nto fail - and (errno == 0) // strto[u]ll did not overflow - and (m_start < m_end) // token was not empty - and (endptr == m_end); // parsed entire token exactly - } - }; - - /*! - @brief return number value for number tokens - - This function translates the last token into the most appropriate - number type (either integer, unsigned integer or floating point), - which is passed back to the caller via the result parameter. - - integral numbers that don't fit into the the range of the respective - type are parsed as number_float_t - - floating-point values do not satisfy std::isfinite predicate - are converted to value_t::null - - throws if the entire string [m_start .. m_cursor) cannot be - interpreted as a number - - @param[out] result @ref basic_json object to receive the number. - @param[in] token the type of the number token - */ - bool get_number(basic_json& result, const token_type token) const - { - assert(m_start != nullptr); - assert(m_start < m_cursor); - assert((token == token_type::value_unsigned) or - (token == token_type::value_integer) or - (token == token_type::value_float)); - - strtonum num_converter(reinterpret_cast<const char*>(m_start), - reinterpret_cast<const char*>(m_cursor)); - - switch (token) - { - case lexer::token_type::value_unsigned: - { - number_unsigned_t val; - if (num_converter.to(val)) - { - // parsing successful - result.m_type = value_t::number_unsigned; - result.m_value = val; - return true; - } - break; - } - - case lexer::token_type::value_integer: - { - number_integer_t val; - if (num_converter.to(val)) - { - // parsing successful - result.m_type = value_t::number_integer; - result.m_value = val; - return true; - } - break; - } - - default: - { - break; - } - } - - // parse float (either explicitly or because a previous conversion - // failed) - number_float_t val; - if (num_converter.to(val)) - { - // parsing successful - result.m_type = value_t::number_float; - result.m_value = val; - - // replace infinity and NAN by null - if (not std::isfinite(result.m_value.number_float)) - { - result.m_type = value_t::null; - result.m_value = basic_json::json_value(); - } - - return true; - } - - // couldn't parse number in any format - return false; - } - - private: - /// optional input stream - std::istream* m_stream = nullptr; - /// line buffer buffer for m_stream - string_t m_line_buffer {}; - /// used for filling m_line_buffer - string_t m_line_buffer_tmp {}; - /// the buffer pointer - const lexer_char_t* m_content = nullptr; - /// pointer to the beginning of the current symbol - const lexer_char_t* m_start = nullptr; - /// pointer for backtracking information - const lexer_char_t* m_marker = nullptr; - /// pointer to the current symbol - const lexer_char_t* m_cursor = nullptr; - /// pointer to the end of the buffer - const lexer_char_t* m_limit = nullptr; - /// the last token type - token_type last_token_type = token_type::end_of_input; - }; - - /*! - @brief syntax analysis - - This class implements a recursive decent parser. - */ - class parser - { - public: - /// a parser reading from a string literal - parser(const char* buff, const parser_callback_t cb = nullptr) - : callback(cb), - m_lexer(reinterpret_cast<const typename lexer::lexer_char_t*>(buff), std::strlen(buff)) - {} - - /// a parser reading from an input stream - parser(std::istream& is, const parser_callback_t cb = nullptr) - : callback(cb), m_lexer(is) - {} - - /// a parser reading from an iterator range with contiguous storage - template<class IteratorType, typename std::enable_if< - std::is_same<typename std::iterator_traits<IteratorType>::iterator_category, std::random_access_iterator_tag>::value - , int>::type - = 0> - parser(IteratorType first, IteratorType last, const parser_callback_t cb = nullptr) - : callback(cb), - m_lexer(reinterpret_cast<const typename lexer::lexer_char_t*>(&(*first)), - static_cast<size_t>(std::distance(first, last))) - {} - - /// public parser interface - basic_json parse() - { - // read first token - get_token(); - - basic_json result = parse_internal(true); - result.assert_invariant(); - - expect(lexer::token_type::end_of_input); - - // return parser result and replace it with null in case the - // top-level value was discarded by the callback function - return result.is_discarded() ? basic_json() : std::move(result); - } - - private: - /// the actual parser - basic_json parse_internal(bool keep) - { - auto result = basic_json(value_t::discarded); - - switch (last_token) - { - case lexer::token_type::begin_object: - { - if (keep and (not callback - or ((keep = callback(depth++, parse_event_t::object_start, result)) != 0))) - { - // explicitly set result to object to cope with {} - result.m_type = value_t::object; - result.m_value = value_t::object; - } - - // read next token - get_token(); - - // closing } -> we are done - if (last_token == lexer::token_type::end_object) - { - get_token(); - if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } - - // no comma is expected here - unexpect(lexer::token_type::value_separator); - - // otherwise: parse key-value pairs - do - { - // ugly, but could be fixed with loop reorganization - if (last_token == lexer::token_type::value_separator) - { - get_token(); - } - - // store key - expect(lexer::token_type::value_string); - const auto key = m_lexer.get_string(); - - bool keep_tag = false; - if (keep) - { - if (callback) - { - basic_json k(key); - keep_tag = callback(depth, parse_event_t::key, k); - } - else - { - keep_tag = true; - } - } - - // parse separator (:) - get_token(); - expect(lexer::token_type::name_separator); - - // parse and add value - get_token(); - auto value = parse_internal(keep); - if (keep and keep_tag and not value.is_discarded()) - { - result[key] = std::move(value); - } - } - while (last_token == lexer::token_type::value_separator); - - // closing } - expect(lexer::token_type::end_object); - get_token(); - if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) - { - result = basic_json(value_t::discarded); - } - - return result; - } - - case lexer::token_type::begin_array: - { - if (keep and (not callback - or ((keep = callback(depth++, parse_event_t::array_start, result)) != 0))) - { - // explicitly set result to object to cope with [] - result.m_type = value_t::array; - result.m_value = value_t::array; - } - - // read next token - get_token(); - - // closing ] -> we are done - if (last_token == lexer::token_type::end_array) - { - get_token(); - if (callback and not callback(--depth, parse_event_t::array_end, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } - - // no comma is expected here - unexpect(lexer::token_type::value_separator); - - // otherwise: parse values - do - { - // ugly, but could be fixed with loop reorganization - if (last_token == lexer::token_type::value_separator) - { - get_token(); - } - - // parse value - auto value = parse_internal(keep); - if (keep and not value.is_discarded()) - { - result.push_back(std::move(value)); - } - } - while (last_token == lexer::token_type::value_separator); - - // closing ] - expect(lexer::token_type::end_array); - get_token(); - if (keep and callback and not callback(--depth, parse_event_t::array_end, result)) - { - result = basic_json(value_t::discarded); - } - - return result; - } - - case lexer::token_type::literal_null: - { - get_token(); - result.m_type = value_t::null; - break; - } - - case lexer::token_type::value_string: - { - const auto s = m_lexer.get_string(); - get_token(); - result = basic_json(s); - break; - } - - case lexer::token_type::literal_true: - { - get_token(); - result.m_type = value_t::boolean; - result.m_value = true; - break; - } - - case lexer::token_type::literal_false: - { - get_token(); - result.m_type = value_t::boolean; - result.m_value = false; - break; - } - - case lexer::token_type::value_unsigned: - case lexer::token_type::value_integer: - case lexer::token_type::value_float: - { - m_lexer.get_number(result, last_token); - get_token(); - break; - } - - default: - { - // the last token was unexpected - unexpect(last_token); - } - } - - if (keep and callback and not callback(depth, parse_event_t::value, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } - - /// get next token from lexer - typename lexer::token_type get_token() - { - last_token = m_lexer.scan(); - return last_token; - } - - void expect(typename lexer::token_type t) const - { - if (t != last_token) - { - std::string error_msg = "parse error - unexpected "; - error_msg += (last_token == lexer::token_type::parse_error ? ("'" + m_lexer.get_token_string() + - "'") : - lexer::token_type_name(last_token)); - error_msg += "; expected " + lexer::token_type_name(t); - JSON_THROW(std::invalid_argument(error_msg)); - } - } - - void unexpect(typename lexer::token_type t) const - { - if (t == last_token) - { - std::string error_msg = "parse error - unexpected "; - error_msg += (last_token == lexer::token_type::parse_error ? ("'" + m_lexer.get_token_string() + - "'") : - lexer::token_type_name(last_token)); - JSON_THROW(std::invalid_argument(error_msg)); - } - } - - private: - /// current level of recursion - int depth = 0; - /// callback function - const parser_callback_t callback = nullptr; - /// the type of the last read token - typename lexer::token_type last_token = lexer::token_type::uninitialized; - /// the lexer - lexer m_lexer; - }; - - public: - /*! - @brief JSON Pointer - - A JSON pointer defines a string syntax for identifying a specific value - within a JSON document. It can be used with functions `at` and - `operator[]`. Furthermore, JSON pointers are the base for JSON patches. - - @sa [RFC 6901](https://tools.ietf.org/html/rfc6901) - - @since version 2.0.0 - */ - class json_pointer - { - /// allow basic_json to access private members - friend class basic_json; - - public: - /*! - @brief create JSON pointer - - Create a JSON pointer according to the syntax described in - [Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3). - - @param[in] s string representing the JSON pointer; if omitted, the - empty string is assumed which references the whole JSON - value - - @throw std::domain_error if reference token is nonempty and does not - begin with a slash (`/`); example: `"JSON pointer must be empty or - begin with /"` - @throw std::domain_error if a tilde (`~`) is not followed by `0` - (representing `~`) or `1` (representing `/`); example: `"escape error: - ~ must be followed with 0 or 1"` - - @liveexample{The example shows the construction several valid JSON - pointers as well as the exceptional behavior.,json_pointer} - - @since version 2.0.0 - */ - explicit json_pointer(const std::string& s = "") - : reference_tokens(split(s)) - {} - - /*! - @brief return a string representation of the JSON pointer - - @invariant For each JSON pointer `ptr`, it holds: - @code {.cpp} - ptr == json_pointer(ptr.to_string()); - @endcode - - @return a string representation of the JSON pointer - - @liveexample{The example shows the result of `to_string`., - json_pointer__to_string} - - @since version 2.0.0 - */ - std::string to_string() const noexcept - { - return std::accumulate(reference_tokens.begin(), - reference_tokens.end(), std::string{}, - [](const std::string & a, const std::string & b) - { - return a + "/" + escape(b); - }); - } - - /// @copydoc to_string() - operator std::string() const - { - return to_string(); - } - - private: - /// remove and return last reference pointer - std::string pop_back() - { - if (is_root()) - { - JSON_THROW(std::domain_error("JSON pointer has no parent")); - } - - auto last = reference_tokens.back(); - reference_tokens.pop_back(); - return last; - } - - /// return whether pointer points to the root document - bool is_root() const - { - return reference_tokens.empty(); - } - - json_pointer top() const - { - if (is_root()) - { - JSON_THROW(std::domain_error("JSON pointer has no parent")); - } - - json_pointer result = *this; - result.reference_tokens = {reference_tokens[0]}; - return result; - } - - /*! - @brief create and return a reference to the pointed to value - - @complexity Linear in the number of reference tokens. - */ - reference get_and_create(reference j) const - { - pointer result = &j; - - // in case no reference tokens exist, return a reference to the - // JSON value j which will be overwritten by a primitive value - for (const auto& reference_token : reference_tokens) - { - switch (result->m_type) - { - case value_t::null: - { - if (reference_token == "0") - { - // start a new array if reference token is 0 - result = &result->operator[](0); - } - else - { - // start a new object otherwise - result = &result->operator[](reference_token); - } - break; - } - - case value_t::object: - { - // create an entry in the object - result = &result->operator[](reference_token); - break; - } - - case value_t::array: - { - // create an entry in the array - result = &result->operator[](static_cast<size_type>(std::stoi(reference_token))); - break; - } - - /* - The following code is only reached if there exists a - reference token _and_ the current value is primitive. In - this case, we have an error situation, because primitive - values may only occur as single value; that is, with an - empty list of reference tokens. - */ - default: - { - JSON_THROW(std::domain_error("invalid value to unflatten")); - } - } - } - - return *result; - } - - /*! - @brief return a reference to the pointed to value - - @note This version does not throw if a value is not present, but tries - to create nested values instead. For instance, calling this function - with pointer `"/this/that"` on a null value is equivalent to calling - `operator[]("this").operator[]("that")` on that value, effectively - changing the null value to an object. - - @param[in] ptr a JSON value - - @return reference to the JSON value pointed to by the JSON pointer - - @complexity Linear in the length of the JSON pointer. - - @throw std::out_of_range if the JSON pointer can not be resolved - @throw std::domain_error if an array index begins with '0' - @throw std::invalid_argument if an array index was not a number - */ - reference get_unchecked(pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - // convert null values to arrays or objects before continuing - if (ptr->m_type == value_t::null) - { - // check if reference token is a number - const bool nums = std::all_of(reference_token.begin(), - reference_token.end(), - [](const char x) - { - return std::isdigit(x); - }); - - // change value to array for numbers or "-" or to object - // otherwise - if (nums or reference_token == "-") - { - *ptr = value_t::array; - } - else - { - *ptr = value_t::object; - } - } - - switch (ptr->m_type) - { - case value_t::object: - { - // use unchecked object access - ptr = &ptr->operator[](reference_token); - break; - } - - case value_t::array: - { - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(std::domain_error("array index must not begin with '0'")); - } - - if (reference_token == "-") - { - // explicitly treat "-" as index beyond the end - ptr = &ptr->operator[](ptr->m_value.array->size()); - } - else - { - // convert array index to number; unchecked access - ptr = &ptr->operator[](static_cast<size_type>(std::stoi(reference_token))); - } - break; - } - - default: - { - JSON_THROW(std::out_of_range("unresolved reference token '" + reference_token + "'")); - } - } - } - - return *ptr; - } - - reference get_checked(pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // note: at performs range check - ptr = &ptr->at(reference_token); - break; - } - - case value_t::array: - { - if (reference_token == "-") - { - // "-" always fails the range check - JSON_THROW(std::out_of_range("array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } - - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(std::domain_error("array index must not begin with '0'")); - } - - // note: at performs range check - ptr = &ptr->at(static_cast<size_type>(std::stoi(reference_token))); - break; - } - - default: - { - JSON_THROW(std::out_of_range("unresolved reference token '" + reference_token + "'")); - } - } - } - - return *ptr; - } - - /*! - @brief return a const reference to the pointed to value - - @param[in] ptr a JSON value - - @return const reference to the JSON value pointed to by the JSON - pointer - */ - const_reference get_unchecked(const_pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // use unchecked object access - ptr = &ptr->operator[](reference_token); - break; - } - - case value_t::array: - { - if (reference_token == "-") - { - // "-" cannot be used for const access - JSON_THROW(std::out_of_range("array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } - - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(std::domain_error("array index must not begin with '0'")); - } - - // use unchecked array access - ptr = &ptr->operator[](static_cast<size_type>(std::stoi(reference_token))); - break; - } - - default: - { - JSON_THROW(std::out_of_range("unresolved reference token '" + reference_token + "'")); - } - } - } - - return *ptr; - } - - const_reference get_checked(const_pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // note: at performs range check - ptr = &ptr->at(reference_token); - break; - } - - case value_t::array: - { - if (reference_token == "-") - { - // "-" always fails the range check - JSON_THROW(std::out_of_range("array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } - - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(std::domain_error("array index must not begin with '0'")); - } - - // note: at performs range check - ptr = &ptr->at(static_cast<size_type>(std::stoi(reference_token))); - break; - } - - default: - { - JSON_THROW(std::out_of_range("unresolved reference token '" + reference_token + "'")); - } - } - } - - return *ptr; - } - - /// split the string input to reference tokens - static std::vector<std::string> split(const std::string& reference_string) - { - std::vector<std::string> result; - - // special case: empty reference string -> no reference tokens - if (reference_string.empty()) - { - return result; - } - - // check if nonempty reference string begins with slash - if (reference_string[0] != '/') - { - JSON_THROW(std::domain_error("JSON pointer must be empty or begin with '/'")); - } - - // extract the reference tokens: - // - slash: position of the last read slash (or end of string) - // - start: position after the previous slash - for ( - // search for the first slash after the first character - size_t slash = reference_string.find_first_of('/', 1), - // set the beginning of the first reference token - start = 1; - // we can stop if start == string::npos+1 = 0 - start != 0; - // set the beginning of the next reference token - // (will eventually be 0 if slash == std::string::npos) - start = slash + 1, - // find next slash - slash = reference_string.find_first_of('/', start)) - { - // use the text between the beginning of the reference token - // (start) and the last slash (slash). - auto reference_token = reference_string.substr(start, slash - start); - - // check reference tokens are properly escaped - for (size_t pos = reference_token.find_first_of('~'); - pos != std::string::npos; - pos = reference_token.find_first_of('~', pos + 1)) - { - assert(reference_token[pos] == '~'); - - // ~ must be followed by 0 or 1 - if (pos == reference_token.size() - 1 or - (reference_token[pos + 1] != '0' and - reference_token[pos + 1] != '1')) - { - JSON_THROW(std::domain_error("escape error: '~' must be followed with '0' or '1'")); - } - } - - // finally, store the reference token - unescape(reference_token); - result.push_back(reference_token); - } - - return result; - } - - private: - /*! - @brief replace all occurrences of a substring by another string - - @param[in,out] s the string to manipulate; changed so that all - occurrences of @a f are replaced with @a t - @param[in] f the substring to replace with @a t - @param[in] t the string to replace @a f - - @pre The search string @a f must not be empty. - - @since version 2.0.0 - */ - static void replace_substring(std::string& s, - const std::string& f, - const std::string& t) - { - assert(not f.empty()); - - for ( - size_t pos = s.find(f); // find first occurrence of f - pos != std::string::npos; // make sure f was found - s.replace(pos, f.size(), t), // replace with t - pos = s.find(f, pos + t.size()) // find next occurrence of f - ); - } - - /// escape tilde and slash - static std::string escape(std::string s) - { - // escape "~"" to "~0" and "/" to "~1" - replace_substring(s, "~", "~0"); - replace_substring(s, "/", "~1"); - return s; - } - - /// unescape tilde and slash - static void unescape(std::string& s) - { - // first transform any occurrence of the sequence '~1' to '/' - replace_substring(s, "~1", "/"); - // then transform any occurrence of the sequence '~0' to '~' - replace_substring(s, "~0", "~"); - } - - /*! - @param[in] reference_string the reference string to the current value - @param[in] value the value to consider - @param[in,out] result the result object to insert values to - - @note Empty objects or arrays are flattened to `null`. - */ - static void flatten(const std::string& reference_string, - const basic_json& value, - basic_json& result) - { - switch (value.m_type) - { - case value_t::array: - { - if (value.m_value.array->empty()) - { - // flatten empty array as null - result[reference_string] = nullptr; - } - else - { - // iterate array and use index as reference string - for (size_t i = 0; i < value.m_value.array->size(); ++i) - { - flatten(reference_string + "/" + std::to_string(i), - value.m_value.array->operator[](i), result); - } - } - break; - } - - case value_t::object: - { - if (value.m_value.object->empty()) - { - // flatten empty object as null - result[reference_string] = nullptr; - } - else - { - // iterate object and use keys as reference string - for (const auto& element : *value.m_value.object) - { - flatten(reference_string + "/" + escape(element.first), - element.second, result); - } - } - break; - } - - default: - { - // add primitive value with its reference string - result[reference_string] = value; - break; - } - } - } - - /*! - @param[in] value flattened JSON - - @return unflattened JSON - */ - static basic_json unflatten(const basic_json& value) - { - if (not value.is_object()) - { - JSON_THROW(std::domain_error("only objects can be unflattened")); - } - - basic_json result; - - // iterate the JSON object values - for (const auto& element : *value.m_value.object) - { - if (not element.second.is_primitive()) - { - JSON_THROW(std::domain_error("values in object must be primitive")); - } - - // assign value to reference pointed to by JSON pointer; Note - // that if the JSON pointer is "" (i.e., points to the whole - // value), function get_and_create returns a reference to - // result itself. An assignment will then create a primitive - // value. - json_pointer(element.first).get_and_create(result) = element.second; - } - - return result; - } - - private: - friend bool operator==(json_pointer const& lhs, - json_pointer const& rhs) noexcept - { - return lhs.reference_tokens == rhs.reference_tokens; - } - - friend bool operator!=(json_pointer const& lhs, - json_pointer const& rhs) noexcept - { - return !(lhs == rhs); - } - - /// the reference tokens - std::vector<std::string> reference_tokens {}; - }; - - ////////////////////////// - // JSON Pointer support // - ////////////////////////// - - /// @name JSON Pointer functions - /// @{ - - /*! - @brief access specified element via JSON Pointer - - Uses a JSON pointer to retrieve a reference to the respective JSON value. - No bound checking is performed. Similar to @ref operator[](const typename - object_t::key_type&), `null` values are created in arrays and objects if - necessary. - - In particular: - - If the JSON pointer points to an object key that does not exist, it - is created an filled with a `null` value before a reference to it - is returned. - - If the JSON pointer points to an array index that does not exist, it - is created an filled with a `null` value before a reference to it - is returned. All indices between the current maximum and the given - index are also filled with `null`. - - The special value `-` is treated as a synonym for the index past the - end. - - @param[in] ptr a JSON pointer - - @return reference to the element pointed to by @a ptr - - @complexity Constant. - - @throw std::out_of_range if the JSON pointer can not be resolved - @throw std::domain_error if an array index begins with '0' - @throw std::invalid_argument if an array index was not a number - - @liveexample{The behavior is shown in the example.,operatorjson_pointer} - - @since version 2.0.0 - */ - reference operator[](const json_pointer& ptr) - { - return ptr.get_unchecked(this); - } - - /*! - @brief access specified element via JSON Pointer - - Uses a JSON pointer to retrieve a reference to the respective JSON value. - No bound checking is performed. The function does not change the JSON - value; no `null` values are created. In particular, the the special value - `-` yields an exception. - - @param[in] ptr JSON pointer to the desired element - - @return const reference to the element pointed to by @a ptr - - @complexity Constant. - - @throw std::out_of_range if the JSON pointer can not be resolved - @throw std::domain_error if an array index begins with '0' - @throw std::invalid_argument if an array index was not a number - - @liveexample{The behavior is shown in the example.,operatorjson_pointer_const} - - @since version 2.0.0 - */ - const_reference operator[](const json_pointer& ptr) const - { - return ptr.get_unchecked(this); - } - - /*! - @brief access specified element via JSON Pointer - - Returns a reference to the element at with specified JSON pointer @a ptr, - with bounds checking. - - @param[in] ptr JSON pointer to the desired element - - @return reference to the element pointed to by @a ptr - - @complexity Constant. - - @throw std::out_of_range if the JSON pointer can not be resolved - @throw std::domain_error if an array index begins with '0' - @throw std::invalid_argument if an array index was not a number - - @liveexample{The behavior is shown in the example.,at_json_pointer} - - @since version 2.0.0 - */ - reference at(const json_pointer& ptr) - { - return ptr.get_checked(this); - } - - /*! - @brief access specified element via JSON Pointer - - Returns a const reference to the element at with specified JSON pointer @a - ptr, with bounds checking. - - @param[in] ptr JSON pointer to the desired element - - @return reference to the element pointed to by @a ptr - - @complexity Constant. - - @throw std::out_of_range if the JSON pointer can not be resolved - @throw std::domain_error if an array index begins with '0' - @throw std::invalid_argument if an array index was not a number - - @liveexample{The behavior is shown in the example.,at_json_pointer_const} - - @since version 2.0.0 - */ - const_reference at(const json_pointer& ptr) const - { - return ptr.get_checked(this); - } - - /*! - @brief return flattened JSON value - - The function creates a JSON object whose keys are JSON pointers (see [RFC - 6901](https://tools.ietf.org/html/rfc6901)) and whose values are all - primitive. The original JSON value can be restored using the @ref - unflatten() function. - - @return an object that maps JSON pointers to primitive values - - @note Empty objects and arrays are flattened to `null` and will not be - reconstructed correctly by the @ref unflatten() function. - - @complexity Linear in the size the JSON value. - - @liveexample{The following code shows how a JSON object is flattened to an - object whose keys consist of JSON pointers.,flatten} - - @sa @ref unflatten() for the reverse function - - @since version 2.0.0 - */ - basic_json flatten() const - { - basic_json result(value_t::object); - json_pointer::flatten("", *this, result); - return result; - } - - /*! - @brief unflatten a previously flattened JSON value - - The function restores the arbitrary nesting of a JSON value that has been - flattened before using the @ref flatten() function. The JSON value must - meet certain constraints: - 1. The value must be an object. - 2. The keys must be JSON pointers (see - [RFC 6901](https://tools.ietf.org/html/rfc6901)) - 3. The mapped values must be primitive JSON types. - - @return the original JSON from a flattened version - - @note Empty objects and arrays are flattened by @ref flatten() to `null` - values and can not unflattened to their original type. Apart from - this example, for a JSON value `j`, the following is always true: - `j == j.flatten().unflatten()`. - - @complexity Linear in the size the JSON value. - - @liveexample{The following code shows how a flattened JSON object is - unflattened into the original nested JSON object.,unflatten} - - @sa @ref flatten() for the reverse function - - @since version 2.0.0 - */ - basic_json unflatten() const - { - return json_pointer::unflatten(*this); - } - - /// @} - - ////////////////////////// - // JSON Patch functions // - ////////////////////////// - - /// @name JSON Patch functions - /// @{ - - /*! - @brief applies a JSON patch - - [JSON Patch](http://jsonpatch.com) defines a JSON document structure for - expressing a sequence of operations to apply to a JSON) document. With - this function, a JSON Patch is applied to the current JSON value by - executing all operations from the patch. - - @param[in] json_patch JSON patch document - @return patched document - - @note The application of a patch is atomic: Either all operations succeed - and the patched document is returned or an exception is thrown. In - any case, the original value is not changed: the patch is applied - to a copy of the value. - - @throw std::out_of_range if a JSON pointer inside the patch could not - be resolved successfully in the current JSON value; example: `"key baz - not found"` - @throw invalid_argument if the JSON patch is malformed (e.g., mandatory - attributes are missing); example: `"operation add must have member path"` - - @complexity Linear in the size of the JSON value and the length of the - JSON patch. As usually only a fraction of the JSON value is affected by - the patch, the complexity can usually be neglected. - - @liveexample{The following code shows how a JSON patch is applied to a - value.,patch} - - @sa @ref diff -- create a JSON patch by comparing two JSON values - - @sa [RFC 6902 (JSON Patch)](https://tools.ietf.org/html/rfc6902) - @sa [RFC 6901 (JSON Pointer)](https://tools.ietf.org/html/rfc6901) - - @since version 2.0.0 - */ - basic_json patch(const basic_json& json_patch) const - { - // make a working copy to apply the patch to - basic_json result = *this; - - // the valid JSON Patch operations - enum class patch_operations {add, remove, replace, move, copy, test, invalid}; - - const auto get_op = [](const std::string op) - { - if (op == "add") - { - return patch_operations::add; - } - if (op == "remove") - { - return patch_operations::remove; - } - if (op == "replace") - { - return patch_operations::replace; - } - if (op == "move") - { - return patch_operations::move; - } - if (op == "copy") - { - return patch_operations::copy; - } - if (op == "test") - { - return patch_operations::test; - } - - return patch_operations::invalid; - }; - - // wrapper for "add" operation; add value at ptr - const auto operation_add = [&result](json_pointer & ptr, basic_json val) - { - // adding to the root of the target document means replacing it - if (ptr.is_root()) - { - result = val; - } - else - { - // make sure the top element of the pointer exists - json_pointer top_pointer = ptr.top(); - if (top_pointer != ptr) - { - result.at(top_pointer); - } - - // get reference to parent of JSON pointer ptr - const auto last_path = ptr.pop_back(); - basic_json& parent = result[ptr]; - - switch (parent.m_type) - { - case value_t::null: - case value_t::object: - { - // use operator[] to add value - parent[last_path] = val; - break; - } - - case value_t::array: - { - if (last_path == "-") - { - // special case: append to back - parent.push_back(val); - } - else - { - const auto idx = std::stoi(last_path); - if (static_cast<size_type>(idx) > parent.size()) - { - // avoid undefined behavior - JSON_THROW(std::out_of_range("array index " + std::to_string(idx) + " is out of range")); - } - else - { - // default case: insert add offset - parent.insert(parent.begin() + static_cast<difference_type>(idx), val); - } - } - break; - } - - default: - { - // if there exists a parent it cannot be primitive - assert(false); // LCOV_EXCL_LINE - } - } - } - }; - - // wrapper for "remove" operation; remove value at ptr - const auto operation_remove = [&result](json_pointer & ptr) - { - // get reference to parent of JSON pointer ptr - const auto last_path = ptr.pop_back(); - basic_json& parent = result.at(ptr); - - // remove child - if (parent.is_object()) - { - // perform range check - auto it = parent.find(last_path); - if (it != parent.end()) - { - parent.erase(it); - } - else - { - JSON_THROW(std::out_of_range("key '" + last_path + "' not found")); - } - } - else if (parent.is_array()) - { - // note erase performs range check - parent.erase(static_cast<size_type>(std::stoi(last_path))); - } - }; - - // type check - if (not json_patch.is_array()) - { - // a JSON patch must be an array of objects - JSON_THROW(std::invalid_argument("JSON patch must be an array of objects")); - } - - // iterate and apply the operations - for (const auto& val : json_patch) - { - // wrapper to get a value for an operation - const auto get_value = [&val](const std::string & op, - const std::string & member, - bool string_type) -> basic_json& - { - // find value - auto it = val.m_value.object->find(member); - - // context-sensitive error message - const auto error_msg = (op == "op") ? "operation" : "operation '" + op + "'"; - - // check if desired value is present - if (it == val.m_value.object->end()) - { - JSON_THROW(std::invalid_argument(error_msg + " must have member '" + member + "'")); - } - - // check if result is of type string - if (string_type and not it->second.is_string()) - { - JSON_THROW(std::invalid_argument(error_msg + " must have string member '" + member + "'")); - } - - // no error: return value - return it->second; - }; - - // type check - if (not val.is_object()) - { - JSON_THROW(std::invalid_argument("JSON patch must be an array of objects")); - } - - // collect mandatory members - const std::string op = get_value("op", "op", true); - const std::string path = get_value(op, "path", true); - json_pointer ptr(path); - - switch (get_op(op)) - { - case patch_operations::add: - { - operation_add(ptr, get_value("add", "value", false)); - break; - } - - case patch_operations::remove: - { - operation_remove(ptr); - break; - } - - case patch_operations::replace: - { - // the "path" location must exist - use at() - result.at(ptr) = get_value("replace", "value", false); - break; - } - - case patch_operations::move: - { - const std::string from_path = get_value("move", "from", true); - json_pointer from_ptr(from_path); - - // the "from" location must exist - use at() - basic_json v = result.at(from_ptr); - - // The move operation is functionally identical to a - // "remove" operation on the "from" location, followed - // immediately by an "add" operation at the target - // location with the value that was just removed. - operation_remove(from_ptr); - operation_add(ptr, v); - break; - } - - case patch_operations::copy: - { - const std::string from_path = get_value("copy", "from", true);; - const json_pointer from_ptr(from_path); - - // the "from" location must exist - use at() - result[ptr] = result.at(from_ptr); - break; - } - - case patch_operations::test: - { - bool success = false; - JSON_TRY - { - // check if "value" matches the one at "path" - // the "path" location must exist - use at() - success = (result.at(ptr) == get_value("test", "value", false)); - } - JSON_CATCH (std::out_of_range&) - { - // ignore out of range errors: success remains false - } - - // throw an exception if test fails - if (not success) - { - JSON_THROW(std::domain_error("unsuccessful: " + val.dump())); - } - - break; - } - - case patch_operations::invalid: - { - // op must be "add", "remove", "replace", "move", "copy", or - // "test" - JSON_THROW(std::invalid_argument("operation value '" + op + "' is invalid")); - } - } - } - - return result; - } - - /*! - @brief creates a diff as a JSON patch - - Creates a [JSON Patch](http://jsonpatch.com) so that value @a source can - be changed into the value @a target by calling @ref patch function. - - @invariant For two JSON values @a source and @a target, the following code - yields always `true`: - @code {.cpp} - source.patch(diff(source, target)) == target; - @endcode - - @note Currently, only `remove`, `add`, and `replace` operations are - generated. - - @param[in] source JSON value to compare from - @param[in] target JSON value to compare against - @param[in] path helper value to create JSON pointers - - @return a JSON patch to convert the @a source to @a target - - @complexity Linear in the lengths of @a source and @a target. - - @liveexample{The following code shows how a JSON patch is created as a - diff for two JSON values.,diff} - - @sa @ref patch -- apply a JSON patch - - @sa [RFC 6902 (JSON Patch)](https://tools.ietf.org/html/rfc6902) - - @since version 2.0.0 - */ - static basic_json diff(const basic_json& source, - const basic_json& target, - const std::string& path = "") - { - // the patch - basic_json result(value_t::array); - - // if the values are the same, return empty patch - if (source == target) - { - return result; - } - - if (source.type() != target.type()) - { - // different types: replace value - result.push_back( - { - {"op", "replace"}, - {"path", path}, - {"value", target} - }); - } - else - { - switch (source.type()) - { - case value_t::array: - { - // first pass: traverse common elements - size_t i = 0; - while (i < source.size() and i < target.size()) - { - // recursive call to compare array values at index i - auto temp_diff = diff(source[i], target[i], path + "/" + std::to_string(i)); - result.insert(result.end(), temp_diff.begin(), temp_diff.end()); - ++i; - } - - // i now reached the end of at least one array - // in a second pass, traverse the remaining elements - - // remove my remaining elements - const auto end_index = static_cast<difference_type>(result.size()); - while (i < source.size()) - { - // add operations in reverse order to avoid invalid - // indices - result.insert(result.begin() + end_index, object( - { - {"op", "remove"}, - {"path", path + "/" + std::to_string(i)} - })); - ++i; - } - - // add other remaining elements - while (i < target.size()) - { - result.push_back( - { - {"op", "add"}, - {"path", path + "/" + std::to_string(i)}, - {"value", target[i]} - }); - ++i; - } - - break; - } - - case value_t::object: - { - // first pass: traverse this object's elements - for (auto it = source.begin(); it != source.end(); ++it) - { - // escape the key name to be used in a JSON patch - const auto key = json_pointer::escape(it.key()); - - if (target.find(it.key()) != target.end()) - { - // recursive call to compare object values at key it - auto temp_diff = diff(it.value(), target[it.key()], path + "/" + key); - result.insert(result.end(), temp_diff.begin(), temp_diff.end()); - } - else - { - // found a key that is not in o -> remove it - result.push_back(object( - { - {"op", "remove"}, - {"path", path + "/" + key} - })); - } - } - - // second pass: traverse other object's elements - for (auto it = target.begin(); it != target.end(); ++it) - { - if (source.find(it.key()) == source.end()) - { - // found a key that is not in this -> add it - const auto key = json_pointer::escape(it.key()); - result.push_back( - { - {"op", "add"}, - {"path", path + "/" + key}, - {"value", it.value()} - }); - } - } - - break; - } - - default: - { - // both primitive type: replace value - result.push_back( - { - {"op", "replace"}, - {"path", path}, - {"value", target} - }); - break; - } - } - } - - return result; - } - - /// @} -}; - -///////////// -// presets // -///////////// - -/*! -@brief default JSON class - -This type is the default specialization of the @ref basic_json class which -uses the standard template types. - -@since version 1.0.0 -*/ -using json = basic_json<>; -} // namespace nlohmann - - -/////////////////////// -// nonmember support // -/////////////////////// - -// specialization of std::swap, and std::hash -namespace std -{ -/*! -@brief exchanges the values of two JSON objects - -@since version 1.0.0 -*/ -template<> -inline void swap(nlohmann::json& j1, - nlohmann::json& j2) noexcept( - is_nothrow_move_constructible<nlohmann::json>::value and - is_nothrow_move_assignable<nlohmann::json>::value - ) -{ - j1.swap(j2); -} - -/// hash value for JSON objects -template<> -struct hash<nlohmann::json> -{ - /*! - @brief return a hash value for a JSON object - - @since version 1.0.0 - */ - std::size_t operator()(const nlohmann::json& j) const - { - // a naive hashing via the string representation - const auto& h = hash<nlohmann::json::string_t>(); - return h(j.dump()); - } -}; -} // namespace std - -/*! -@brief user-defined string literal for JSON values - -This operator implements a user-defined string literal for JSON objects. It -can be used by adding `"_json"` to a string literal and returns a JSON object -if no parse error occurred. - -@param[in] s a string representation of a JSON object -@param[in] n the length of string @a s -@return a JSON object - -@since version 1.0.0 -*/ -inline nlohmann::json operator "" _json(const char* s, std::size_t n) -{ - return nlohmann::json::parse(s, s + n); -} - -/*! -@brief user-defined string literal for JSON pointer - -This operator implements a user-defined string literal for JSON Pointers. It -can be used by adding `"_json_pointer"` to a string literal and returns a JSON pointer -object if no parse error occurred. - -@param[in] s a string representation of a JSON Pointer -@param[in] n the length of string @a s -@return a JSON pointer object - -@since version 2.0.0 -*/ -inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std::size_t n) -{ - return nlohmann::json::json_pointer(std::string(s, n)); -} - -// restore GCC/clang diagnostic settings -#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) - #pragma GCC diagnostic pop -#endif - -// clean up -#undef JSON_CATCH -#undef JSON_DEPRECATED -#undef JSON_THROW -#undef JSON_TRY - -#endif |