libstdc++: erase_if.h Source File

libstdc++

erase_if.h
Go to the documentation of this file.
1// <bits/erase_if.h> -*- C++ -*-
2
3// Copyright (C) 2015-2026 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/erase_if.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly.
28 */
29
30#ifndef _GLIBCXX_ERASE_IF_H
31#define _GLIBCXX_ERASE_IF_H 1
32
33#ifdef _GLIBCXX_SYSHDR
34#pragma GCC system_header
35#endif
36
37#include <bits/c++config.h>
38#include <bits/stl_algobase.h>
39
40// Used by C++17 containers and Library Fundamentals v2 headers.
41#if __cplusplus >= 201402L
42namespace std
43{
44_GLIBCXX_BEGIN_NAMESPACE_VERSION
45
46 namespace __detail
47 {
48 template<typename _Container, typename _UnsafeContainer,
49 typename _Predicate>
50 _GLIBCXX20_CONSTEXPR
51 typename _Container::size_type
52 __erase_if(_Container& __cont, _UnsafeContainer& __ucont,
53 _Predicate __pred)
54 {
55 const auto __osz = __ucont.size();
56 const auto __end = __ucont.end();
57 auto __removed = std::__remove_if(__ucont.begin(), __end,
58 std::move(__pred));
59 if (__removed != __end)
60 {
61 __cont.erase(__niter_wrap(__cont.begin(), __removed),
62 __cont.end());
63 return __osz - __ucont.size();
64 }
65
66 return 0;
67 }
68
69 template<typename _Container, typename _UnsafeContainer,
70 typename _Predicate>
71 typename _Container::size_type
72 __erase_nodes_if(_Container& __cont, _UnsafeContainer& __ucont,
73 _Predicate __pred)
74 {
75 typename _Container::size_type __num = 0;
76 for (auto __iter = __ucont.begin(), __last = __ucont.end();
77 __iter != __last;)
78 {
79 if (__pred(*__iter))
80 {
81 __iter = __cont.erase(__iter);
82 ++__num;
83 }
84 else
85 ++__iter;
86 }
87 return __num;
88 }
89 } // namespace __detail
90
91_GLIBCXX_END_NAMESPACE_VERSION
92} // namespace std
93#endif // C++14
94
95#endif // _GLIBCXX_ERASE_IF_H
stl_algobase.h
c++config.h
std::move
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition move.h:138
std
ISO C++ entities toplevel namespace is std.
std::__detail
Implementation details not part of the namespace std interface.