Commit | Line | Data |
---|---|---|
e2882c85 | 1 | /* Copyright (C) 2017-2018 Free Software Foundation, Inc. |
9c541725 PA |
2 | |
3 | This file is part of GDB. | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 3 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
17 | ||
18 | #ifndef COMMON_TRAITS_H | |
19 | #define COMMON_TRAITS_H | |
20 | ||
22796e97 PA |
21 | #include <type_traits> |
22 | ||
debed3db PA |
23 | /* GCC does not understand __has_feature. */ |
24 | #if !defined(__has_feature) | |
25 | # define __has_feature(x) 0 | |
26 | #endif | |
27 | ||
28 | /* HAVE_IS_TRIVIALLY_COPYABLE is defined as 1 iff | |
29 | std::is_trivially_copyable is available. GCC only implemented it | |
30 | in GCC 5. */ | |
31 | #if (__has_feature(is_trivially_copyable) \ | |
32 | || (defined __GNUC__ && __GNUC__ >= 5)) | |
33 | # define HAVE_IS_TRIVIALLY_COPYABLE 1 | |
34 | #endif | |
35 | ||
9c541725 PA |
36 | namespace gdb { |
37 | ||
38 | /* Pre C++14-safe (CWG 1558) version of C++17's std::void_t. See | |
39 | <http://en.cppreference.com/w/cpp/types/void_t>. */ | |
40 | ||
41 | template<typename... Ts> | |
42 | struct make_void { typedef void type; }; | |
43 | ||
44 | template<typename... Ts> | |
45 | using void_t = typename make_void<Ts...>::type; | |
46 | ||
22796e97 | 47 | /* A few trait helpers, mainly stolen from libstdc++. Uppercase |
b0b92aeb PA |
48 | because "and/or", etc. are reserved keywords. */ |
49 | ||
50 | template<typename Predicate> | |
51 | struct Not : public std::integral_constant<bool, !Predicate::value> | |
52 | {}; | |
53 | ||
54 | template<typename...> | |
55 | struct Or; | |
56 | ||
57 | template<> | |
58 | struct Or<> : public std::false_type | |
59 | {}; | |
60 | ||
61 | template<typename B1> | |
62 | struct Or<B1> : public B1 | |
63 | {}; | |
64 | ||
65 | template<typename B1, typename B2> | |
66 | struct Or<B1, B2> | |
67 | : public std::conditional<B1::value, B1, B2>::type | |
68 | {}; | |
69 | ||
70 | template<typename B1,typename B2,typename B3, typename... Bn> | |
71 | struct Or<B1, B2, B3, Bn...> | |
72 | : public std::conditional<B1::value, B1, Or<B2, B3, Bn...>>::type | |
73 | {}; | |
22796e97 PA |
74 | |
75 | template<typename...> | |
76 | struct And; | |
77 | ||
78 | template<> | |
79 | struct And<> : public std::true_type | |
80 | {}; | |
81 | ||
82 | template<typename B1> | |
83 | struct And<B1> : public B1 | |
84 | {}; | |
85 | ||
86 | template<typename B1, typename B2> | |
87 | struct And<B1, B2> | |
88 | : public std::conditional<B1::value, B2, B1>::type | |
89 | {}; | |
90 | ||
91 | template<typename B1, typename B2, typename B3, typename... Bn> | |
92 | struct And<B1, B2, B3, Bn...> | |
93 | : public std::conditional<B1::value, And<B2, B3, Bn...>, B1>::type | |
94 | {}; | |
95 | ||
b0b92aeb PA |
96 | /* Concepts-light-like helper to make SFINAE logic easier to read. */ |
97 | template<typename Condition> | |
98 | using Requires = typename std::enable_if<Condition::value, void>::type; | |
9c541725 PA |
99 | } |
100 | ||
101 | #endif /* COMMON_TRAITS_H */ |