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#ifndef MAPBOX_UTIL_OPTIONAL_HPP
#define MAPBOX_UTIL_OPTIONAL_HPP
#pragma message("This implementation of optional is deprecated. See https://github.com/mapbox/variant/issues/64.")
#include <type_traits>
#include <utility>
#include <mapbox/variant.hpp>
namespace mapbox {
namespace util {
template <typename T>
class optional
{
static_assert(!std::is_reference<T>::value, "optional doesn't support references");
struct none_type
{
};
variant<none_type, T> variant_;
public:
optional() = default;
optional(optional const& rhs)
{
if (this != &rhs)
{ // protect against invalid self-assignment
variant_ = rhs.variant_;
}
}
optional(T const& v) { variant_ = v; }
explicit operator bool() const noexcept { return variant_.template is<T>(); }
T const& get() const { return variant_.template get<T>(); }
T& get() { return variant_.template get<T>(); }
T const& operator*() const { return this->get(); }
T operator*() { return this->get(); }
optional& operator=(T const& v)
{
variant_ = v;
return *this;
}
optional& operator=(optional const& rhs)
{
if (this != &rhs)
{
variant_ = rhs.variant_;
}
return *this;
}
template <typename... Args>
void emplace(Args&&... args)
{
variant_ = T{std::forward<Args>(args)...};
}
void reset() { variant_ = none_type{}; }
}; // class optional
} // namespace util
} // namespace mapbox
#endif // MAPBOX_UTIL_OPTIONAL_HPP
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