libstdc++: c++io.h Source File

libstdc++

c++io.h
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1// Underlying io library details -*- C++ -*-
2
3// Copyright (C) 2000-2026 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/c++io.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{ios}
28 */
29
30// c_io_stdio.h - Defines for using "C" stdio.h
31
32#ifndef _GLIBCXX_CXX_IO_H
33#define _GLIBCXX_CXX_IO_H 1
34
35#include <cstdio>
36#include <bits/gthr.h>
37
38namespace std _GLIBCXX_VISIBILITY(default)
39{
40_GLIBCXX_BEGIN_NAMESPACE_VERSION
41
42#ifdef __GTHREAD_LEGACY_MUTEX_T
43 // The layout of __gthread_mutex_t changed in GCC 13, but libstdc++ doesn't
44 // actually use the basic_filebuf::_M_lock member, so define it consistently
45 // with the old __gthread_mutex_t to avoid an unnecessary layout change:
46 typedef __GTHREAD_LEGACY_MUTEX_T __c_lock;
47#else
48 typedef __gthread_mutex_t __c_lock;
49#endif
50
51 // for basic_file.h
52 typedef FILE __c_file;
53
54_GLIBCXX_END_NAMESPACE_VERSION
55} // namespace
56
57#endif
cstdio
std
ISO C++ entities toplevel namespace is std.