blob: e14f92b253b726b6a14fa3727de4855aaeff9a6b (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
/*
* Copyright (C) 2017 Mentor Graphics Development (Deutschland) GmbH
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef TMCAGLWM_RESULT_HPP
#define TMCAGLWM_RESULT_HPP
#include <experimental/optional>
#include <functional>
namespace wm {
using std::experimental::optional;
using std::experimental::nullopt;
// We only ever return a string as an error - so just parametrize
// this over result type T
template <typename T>
struct result {
char const *e;
optional<T> t;
bool is_ok() const { return this->t != nullopt; }
bool is_err() const { return this->e != nullptr; }
T unwrap() {
if (this->e != nullptr) {
throw std::logic_error(this->e);
}
return this->t.value();
}
operator T() { return this->unwrap(); }
char const *unwrap_err() { return this->e; }
optional<T> const &ok() const { return this->t; }
optional<char const *> err() const {
return this->e ? optional<char const *>(this->e) : nullopt;
}
result<T> map_err(std::function<char const *(char const *)> f);
};
template <typename T>
struct result<T> Err(char const *e) {
return result<T>{e, nullopt};
}
template <typename T>
struct result<T> Ok(T t) {
return result<T>{nullptr, t};
}
template <typename T>
result<T> result<T>::map_err(std::function<char const *(char const *)> f) {
if (this->is_err()) {
return Err<T>(f(this->e));
}
return *this;
}
} // namespace wm
#endif // TMCAGLWM_RESULT_HPP
|
