libstdc++: iostream Source File

libstdc++

iostream
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1// Standard iostream objects -*- C++ -*-
2
3// Copyright (C) 1997-2026 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 include/iostream
26 * This is a Standard C++ Library header.
27 */
28
29//
30// ISO C++ 14882: 27.3 Standard iostream objects
31//
32
33#ifndef _GLIBCXX_IOSTREAM
34#define _GLIBCXX_IOSTREAM 1
35
36#ifdef _GLIBCXX_SYSHDR
37#pragma GCC system_header
38#endif
39
40#include <bits/requires_hosted.h> // iostreams
41
42#include <ios>
43#include <ostream>
44#include <istream>
45
46namespace std _GLIBCXX_VISIBILITY(default)
47{
48_GLIBCXX_BEGIN_NAMESPACE_VERSION
49
50 /**
51 * @name Standard Stream Objects
52 *
53 * The `<iostream>` header declares the eight *standard stream objects*.
54 * For other declarations, see
55 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/io.html
56 * and the @link iosfwd I/O forward declarations @endlink
57 *
58 * They are required by default to cooperate with the global C
59 * library's `FILE` streams, and to be available during program
60 * startup and termination. For more information, see the section of the
61 * manual linked to above.
62 */
63 ///@{
64 extern istream cin; ///< Linked to standard input
65 extern ostream cout; ///< Linked to standard output
66 extern ostream cerr; ///< Linked to standard error (unbuffered)
67 extern ostream clog; ///< Linked to standard error (buffered)
68
69#ifdef _GLIBCXX_USE_WCHAR_T
70 extern wistream wcin; ///< Linked to standard input
71 extern wostream wcout; ///< Linked to standard output
72 extern wostream wcerr; ///< Linked to standard error (unbuffered)
73 extern wostream wclog; ///< Linked to standard error (buffered)
74#endif
75 ///@}
76
77 // For construction of filebuffers for cout, cin, cerr, clog et. al.
78 // When the init_priority attribute is usable, we do this initialization
79 // in the compiled library instead (src/c++98/globals_io.cc).
80#if !(_GLIBCXX_USE_INIT_PRIORITY_ATTRIBUTE \
81 && __has_attribute(__init_priority__))
82 static ios_base::Init __ioinit;
83#elif defined(_GLIBCXX_SYMVER_GNU) && defined(__ELF__)
84 __extension__ __asm (".globl _ZSt21ios_base_library_initv");
85#endif
86
87_GLIBCXX_END_NAMESPACE_VERSION
88} // namespace
89
90#endif /* _GLIBCXX_IOSTREAM */
ios
istream
ostream
requires_hosted.h
std::ostream
basic_ostream< char > ostream
Base class for char output streams.
Definition iosfwd.h:84
std::istream
basic_istream< char > istream
Base class for char input streams.
Definition iosfwd.h:81
std::wostream
basic_ostream< wchar_t > wostream
Base class for wchar_t output streams.
Definition iosfwd.h:101
std::wistream
basic_istream< wchar_t > wistream
Base class for wchar_t input streams.
Definition iosfwd.h:98
std
ISO C++ entities toplevel namespace is std.
std::wclog
wostream wclog
Linked to standard error (buffered).
std::wcout
wostream wcout
Linked to standard output.
std::cerr
ostream cerr
Linked to standard error (unbuffered).
std::clog
ostream clog
Linked to standard error (buffered).
std::cout
ostream cout
Linked to standard output.
std::wcin
wistream wcin
Linked to standard input.
std::wcerr
wostream wcerr
Linked to standard error (unbuffered).
std::cin
istream cin
Linked to standard input.