source: mainline/uspace/lib/cpp/include/internal/functional/invoke.hpp@ 8f8f1d1e

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 8f8f1d1e was 8f8f1d1e, checked in by Dzejrou <dzejrou@…>, 7 years ago

cpp: removed usage of _v aliases and added forward declarations instead, this avoids possible circular reference

  • Property mode set to 100644
File size: 3.3 KB
Line 
1/*
2 * Copyright (c) 2018 Jaroslav Jindrak
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef LIBCPP_INTERNAL_FUNCTIONAL_INVOKE
30#define LIBCPP_INTERNAL_FUNCTIONAL_INVOKE
31
32#include <internal/utility/declval.hpp>
33#include <internal/utility/forward_move.hpp>
34
35namespace std
36{
37 template<class>
38 struct is_member_function_pointer;
39
40 template<class, class>
41 struct is_base_of;
42
43 template<class>
44 struct is_member_object_pointer;
45}
46
47namespace std::aux
48{
49 /**
50 * 20.9.2, requirements:
51 */
52
53 template<class R, class T, class T1, class... Ts>
54 decltype(auto) invoke(R T::* f, T1&& t1, Ts&&... args)
55 {
56 if constexpr (is_member_function_pointer<decltype(f)>::value)
57 {
58 if constexpr (is_base_of<T, remove_reference_t<T1>>::value)
59 // (1.1)
60 return (t1.*f)(forward<Ts>(args)...);
61 else
62 // (1.2)
63 return ((*t1).*f)(forward<Ts>(args)...);
64 }
65 else if constexpr (is_member_object_pointer<decltype(f)>::value && sizeof...(args) == 0)
66 {
67 /**
68 * Note: Standard requires to N be equal to 1, but we take t1 directly
69 * so we need sizeof...(args) to be 0.
70 */
71 if constexpr (is_base_of<T, remove_reference_t<T1>>::value)
72 // (1.3)
73 return t1.*f;
74 else
75 // (1.4)
76 return (*t1).*f;
77 }
78 else
79
80 /**
81 * Note: If this condition holds this will not be reachable,
82 * but a new addition to the standard (17.7 point (8.1))
83 * prohibits us from simply using false as the condition here,
84 * so we use this because we know it is false here.
85 */
86 static_assert(is_member_function_pointer<decltype(f)>::value, "invalid invoke");
87 }
88
89 template<class F, class... Args>
90 decltype(auto) invoke(F&& f, Args&&... args)
91 {
92 // (1.5)
93 return f(forward<Args>(args)...);
94 }
95}
96
97#endif
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