libstdc++
std_abs.h
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1 // -*- C++ -*- C library enhancements header.
2 
3 // Copyright (C) 2016-2019 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/std_abs.h
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{cmath, cstdlib}
28  */
29 
30 #ifndef _GLIBCXX_BITS_STD_ABS_H
31 #define _GLIBCXX_BITS_STD_ABS_H
32 
33 #pragma GCC system_header
34 
35 #include <bits/c++config.h>
36 
37 #define _GLIBCXX_INCLUDE_NEXT_C_HEADERS
38 #include_next <stdlib.h>
39 #ifdef __CORRECT_ISO_CPP_MATH_H_PROTO
40 # include_next <math.h>
41 #endif
42 #undef _GLIBCXX_INCLUDE_NEXT_C_HEADERS
43 
44 #undef abs
45 
46 extern "C++"
47 {
48 namespace std _GLIBCXX_VISIBILITY(default)
49 {
50 _GLIBCXX_BEGIN_NAMESPACE_VERSION
51 
52  using ::abs;
53 
54 #ifndef __CORRECT_ISO_CPP_STDLIB_H_PROTO
55  inline long
56  abs(long __i) { return __builtin_labs(__i); }
57 #endif
58 
59 #ifdef _GLIBCXX_USE_LONG_LONG
60  inline long long
61  abs(long long __x) { return __builtin_llabs (__x); }
62 #endif
63 
64 // _GLIBCXX_RESOLVE_LIB_DEFECTS
65 // 2192. Validity and return type of std::abs(0u) is unclear
66 // 2294. <cstdlib> should declare abs(double)
67 // 2735. std::abs(short), std::abs(signed char) and others should return int
68 
69 #ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
70  inline _GLIBCXX_CONSTEXPR double
71  abs(double __x)
72  { return __builtin_fabs(__x); }
73 
74  inline _GLIBCXX_CONSTEXPR float
75  abs(float __x)
76  { return __builtin_fabsf(__x); }
77 
78  inline _GLIBCXX_CONSTEXPR long double
79  abs(long double __x)
80  { return __builtin_fabsl(__x); }
81 #endif
82 
83 #if defined(__GLIBCXX_TYPE_INT_N_0)
84  inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_0
85  abs(__GLIBCXX_TYPE_INT_N_0 __x) { return __x >= 0 ? __x : -__x; }
86 #endif
87 #if defined(__GLIBCXX_TYPE_INT_N_1)
88  inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_1
89  abs(__GLIBCXX_TYPE_INT_N_1 __x) { return __x >= 0 ? __x : -__x; }
90 #endif
91 #if defined(__GLIBCXX_TYPE_INT_N_2)
92  inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_2
93  abs(__GLIBCXX_TYPE_INT_N_2 __x) { return __x >= 0 ? __x : -__x; }
94 #endif
95 #if defined(__GLIBCXX_TYPE_INT_N_3)
96  inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_3
97  abs(__GLIBCXX_TYPE_INT_N_3 __x) { return __x >= 0 ? __x : -__x; }
98 #endif
99 
100 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
101  inline _GLIBCXX_CONSTEXPR
102  __float128
103  abs(__float128 __x)
104  { return __x < 0 ? -__x : __x; }
105 #endif
106 
107 _GLIBCXX_END_NAMESPACE_VERSION
108 } // namespace
109 } // extern "C"++"
110 
111 #endif // _GLIBCXX_BITS_STD_ABS_H
ISO C++ entities toplevel namespace is std.
_Tp abs(const complex< _Tp > &)
Return magnitude of z.
Definition: complex:623