1 // Standard iostream objects -*- C++ -*-
3 // Copyright (C) 1997-2025 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file include/iostream
26 * This is a Standard C++ Library header.
30 // ISO C++ 14882: 27.3 Standard iostream objects
33 #ifndef _GLIBCXX_IOSTREAM
34 #define _GLIBCXX_IOSTREAM 1
36 #ifdef _GLIBCXX_SYSHDR
37 #pragma GCC system_header
40 #include <bits/requires_hosted.h> // iostreams
42 #include <bits/c++config.h>
46 namespace std _GLIBCXX_VISIBILITY(default)
48 _GLIBCXX_BEGIN_NAMESPACE_VERSION
51 * @name Standard Stream Objects
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
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.
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)
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)
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");
87 _GLIBCXX_END_NAMESPACE_VERSION
90 #endif /* _GLIBCXX_IOSTREAM */