1 | // Implementation of INVOKE -*- C++ -*- |
2 | |
3 | // Copyright (C) 2016-2017 Free Software Foundation, Inc. |
4 | // |
5 | // This file is part of the GNU ISO C++ Library. This library is free |
6 | // software; you can redistribute it and/or modify it under the |
7 | // terms of the GNU General Public License as published by the |
8 | // Free Software Foundation; either version 3, or (at your option) |
9 | // any later version. |
10 | |
11 | // This library is distributed in the hope that it will be useful, |
12 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | // GNU General Public License for more details. |
15 | |
16 | // Under Section 7 of GPL version 3, you are granted additional |
17 | // permissions described in the GCC Runtime Library Exception, version |
18 | // 3.1, as published by the Free Software Foundation. |
19 | |
20 | // You should have received a copy of the GNU General Public License and |
21 | // a copy of the GCC Runtime Library Exception along with this program; |
22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
23 | // <http://www.gnu.org/licenses/>. |
24 | |
25 | /** @file include/bits/invoke.h |
26 | * This is an internal header file, included by other library headers. |
27 | * Do not attempt to use it directly. @headername{functional} |
28 | */ |
29 | |
30 | #ifndef _GLIBCXX_INVOKE_H |
31 | #define _GLIBCXX_INVOKE_H 1 |
32 | |
33 | #pragma GCC system_header |
34 | |
35 | #if __cplusplus < 201103L |
36 | # include <bits/c++0x_warning.h> |
37 | #else |
38 | |
39 | #include <type_traits> |
40 | |
41 | namespace std _GLIBCXX_VISIBILITY(default) |
42 | { |
43 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |
44 | |
45 | /** |
46 | * @addtogroup utilities |
47 | * @{ |
48 | */ |
49 | |
50 | // Used by __invoke_impl instead of std::forward<_Tp> so that a |
51 | // reference_wrapper is converted to an lvalue-reference. |
52 | template<typename _Tp, typename _Up = typename __inv_unwrap<_Tp>::type> |
53 | constexpr _Up&& |
54 | __invfwd(typename remove_reference<_Tp>::type& __t) noexcept |
55 | { return static_cast<_Up&&>(__t); } |
56 | |
57 | template<typename _Res, typename _Fn, typename... _Args> |
58 | constexpr _Res |
59 | __invoke_impl(__invoke_other, _Fn&& __f, _Args&&... __args) |
60 | { return std::forward<_Fn>(__f)(std::forward<_Args>(__args)...); } |
61 | |
62 | template<typename _Res, typename _MemFun, typename _Tp, typename... _Args> |
63 | constexpr _Res |
64 | __invoke_impl(__invoke_memfun_ref, _MemFun&& __f, _Tp&& __t, |
65 | _Args&&... __args) |
66 | { return (__invfwd<_Tp>(__t).*__f)(std::forward<_Args>(__args)...); } |
67 | |
68 | template<typename _Res, typename _MemFun, typename _Tp, typename... _Args> |
69 | constexpr _Res |
70 | __invoke_impl(__invoke_memfun_deref, _MemFun&& __f, _Tp&& __t, |
71 | _Args&&... __args) |
72 | { |
73 | return ((*std::forward<_Tp>(__t)).*__f)(std::forward<_Args>(__args)...); |
74 | } |
75 | |
76 | template<typename _Res, typename _MemPtr, typename _Tp> |
77 | constexpr _Res |
78 | __invoke_impl(__invoke_memobj_ref, _MemPtr&& __f, _Tp&& __t) |
79 | { return __invfwd<_Tp>(__t).*__f; } |
80 | |
81 | template<typename _Res, typename _MemPtr, typename _Tp> |
82 | constexpr _Res |
83 | __invoke_impl(__invoke_memobj_deref, _MemPtr&& __f, _Tp&& __t) |
84 | { return (*std::forward<_Tp>(__t)).*__f; } |
85 | |
86 | /// Invoke a callable object. |
87 | template<typename _Callable, typename... _Args> |
88 | constexpr typename __invoke_result<_Callable, _Args...>::type |
89 | __invoke(_Callable&& __fn, _Args&&... __args) |
90 | noexcept(__is_nothrow_invocable<_Callable, _Args...>::value) |
91 | { |
92 | using __result = __invoke_result<_Callable, _Args...>; |
93 | using __type = typename __result::type; |
94 | using __tag = typename __result::__invoke_type; |
95 | return std::__invoke_impl<__type>(__tag{}, std::forward<_Callable>(__fn), |
96 | std::forward<_Args>(__args)...); |
97 | } |
98 | |
99 | _GLIBCXX_END_NAMESPACE_VERSION |
100 | } // namespace std |
101 | |
102 | #endif // C++11 |
103 | |
104 | #endif // _GLIBCXX_INVOKE_H |
105 | |