libstdc++
typeindex
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1// C++11 <typeindex> -*- C++ -*-
2
3// Copyright (C) 2010-2022 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/typeindex
26 * This is a Standard C++ Library header.
27 */
28
29#ifndef _GLIBCXX_TYPEINDEX
30#define _GLIBCXX_TYPEINDEX 1
31
32#pragma GCC system_header
33
34#if __cplusplus < 201103L
35# include <bits/c++0x_warning.h>
36#else
37
38#include <typeinfo>
39#if __cplusplus > 201703L
40# include <compare>
41#endif
42
43namespace std _GLIBCXX_VISIBILITY(default)
44{
45_GLIBCXX_BEGIN_NAMESPACE_VERSION
46
47 /**
48 * @brief Class type_index
49 * @ingroup utilities
50 *
51 * The class type_index provides a simple wrapper for type_info
52 * which can be used as an index type in associative containers
53 * (23.6) and in unordered associative containers (23.7).
54 */
55 struct type_index
56 {
57 type_index(const type_info& __rhs) noexcept
58 : _M_target(&__rhs) { }
59
60 bool
61 operator==(const type_index& __rhs) const noexcept
62 { return *_M_target == *__rhs._M_target; }
63
64#if ! __cpp_lib_three_way_comparison
65 bool
66 operator!=(const type_index& __rhs) const noexcept
67 { return *_M_target != *__rhs._M_target; }
68#endif
69
70 bool
71 operator<(const type_index& __rhs) const noexcept
72 { return _M_target->before(*__rhs._M_target); }
73
74 bool
75 operator<=(const type_index& __rhs) const noexcept
76 { return !__rhs._M_target->before(*_M_target); }
77
78 bool
79 operator>(const type_index& __rhs) const noexcept
80 { return __rhs._M_target->before(*_M_target); }
81
82 bool
83 operator>=(const type_index& __rhs) const noexcept
84 { return !_M_target->before(*__rhs._M_target); }
85
86#if __cpp_lib_three_way_comparison
87 strong_ordering
88 operator<=>(const type_index& __rhs) const noexcept
89 {
90 if (*_M_target == *__rhs._M_target)
91 return strong_ordering::equal;
92 if (_M_target->before(*__rhs._M_target))
93 return strong_ordering::less;
94 return strong_ordering::greater;
95 }
96#endif
97
98 size_t
99 hash_code() const noexcept
100 { return _M_target->hash_code(); }
101
102 const char*
103 name() const noexcept
104 { return _M_target->name(); }
105
106 private:
107 const type_info* _M_target;
108 };
109
110 template<typename _Tp> struct hash;
111
112 /// std::hash specialization for type_index.
113 template<>
114 struct hash<type_index>
115 {
116 typedef size_t result_type;
117 typedef type_index argument_type;
118
119 size_t
120 operator()(const type_index& __ti) const noexcept
121 { return __ti.hash_code(); }
122 };
123
124_GLIBCXX_END_NAMESPACE_VERSION
125} // namespace std
126
127#endif // C++11
128
129#endif // _GLIBCXX_TYPEINDEX