libstdc++: intcmp.h Source File

libstdc++

intcmp.h
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1// Integer comparison functions -*- C++ -*-
2
3// Copyright (C) 2020-2026 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 bits/intcmp.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{utility}
28 */
29
30#ifndef _GLIBCXX_INTCMP_H
31#define _GLIBCXX_INTCMP_H 1
32
33#ifdef _GLIBCXX_SYSHDR
34#pragma GCC system_header
35#endif
36
37#include <bits/version.h>
38
39#ifdef __glibcxx_integer_comparison_functions // C++ >= 20
40
41#include <type_traits>
42#include <ext/numeric_traits.h> // __int_traits
43
44namespace std _GLIBCXX_VISIBILITY(default)
45{
46_GLIBCXX_BEGIN_NAMESPACE_VERSION
47
48 template<typename _Tp, typename _Up>
49 constexpr bool
50 cmp_equal(_Tp __t, _Up __u) noexcept
51 {
52 static_assert(__is_signed_or_unsigned_integer<_Tp>::value);
53 static_assert(__is_signed_or_unsigned_integer<_Up>::value);
54
55 if constexpr (is_signed_v<_Tp> == is_signed_v<_Up>)
56 return __t == __u;
57 else if constexpr (is_signed_v<_Tp>)
58 return __t >= 0 && make_unsigned_t<_Tp>(__t) == __u;
59 else
60 return __u >= 0 && __t == make_unsigned_t<_Up>(__u);
61 }
62
63 template<typename _Tp, typename _Up>
64 constexpr bool
65 cmp_not_equal(_Tp __t, _Up __u) noexcept
66 { return !std::cmp_equal(__t, __u); }
67
68 template<typename _Tp, typename _Up>
69 constexpr bool
70 cmp_less(_Tp __t, _Up __u) noexcept
71 {
72 static_assert(__is_signed_or_unsigned_integer<_Tp>::value);
73 static_assert(__is_signed_or_unsigned_integer<_Up>::value);
74
75 if constexpr (is_signed_v<_Tp> == is_signed_v<_Up>)
76 return __t < __u;
77 else if constexpr (is_signed_v<_Tp>)
78 return __t < 0 || make_unsigned_t<_Tp>(__t) < __u;
79 else
80 return __u >= 0 && __t < make_unsigned_t<_Up>(__u);
81 }
82
83 template<typename _Tp, typename _Up>
84 constexpr bool
85 cmp_greater(_Tp __t, _Up __u) noexcept
86 { return std::cmp_less(__u, __t); }
87
88 template<typename _Tp, typename _Up>
89 constexpr bool
90 cmp_less_equal(_Tp __t, _Up __u) noexcept
91 { return !std::cmp_less(__u, __t); }
92
93 template<typename _Tp, typename _Up>
94 constexpr bool
95 cmp_greater_equal(_Tp __t, _Up __u) noexcept
96 { return !std::cmp_less(__t, __u); }
97
98 template<typename _Res, typename _Tp>
99 constexpr bool
100 in_range(_Tp __t) noexcept
101 {
102 static_assert(__is_signed_or_unsigned_integer<_Res>::value);
103 static_assert(__is_signed_or_unsigned_integer<_Tp>::value);
104 using __gnu_cxx::__int_traits;
105
106 if constexpr (is_signed_v<_Tp> == is_signed_v<_Res>)
107 return __int_traits<_Res>::__min <= __t
108 && __t <= __int_traits<_Res>::__max;
109 else if constexpr (is_signed_v<_Tp>)
110 return __t >= 0
111 && make_unsigned_t<_Tp>(__t) <= __int_traits<_Res>::__max;
112 else
113 return __t <= make_unsigned_t<_Res>(__int_traits<_Res>::__max);
114 }
115
116_GLIBCXX_END_NAMESPACE_VERSION
117} // namespace
118
119#endif // __glibcxx_integer_comparison_functions
120#endif // _GLIBCXX_INTCMP_H
type_traits
version.h
std::make_unsigned_t
typename make_unsigned< _Tp >::type make_unsigned_t
Alias template for make_unsigned.
Definition type_traits:2250
std
ISO C++ entities toplevel namespace is std.
__gnu_cxx::__int_traits
__numeric_traits_integer< _Tp > __int_traits
Convenience alias for __numeric_traits<integer-type>.
Definition ext/numeric_traits.h:134
numeric_traits.h