libstdc++-v3/include/std/iostream

// Standard iostream objects -*- C++ -*-

// Copyright (C) 1997-2025 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file include/iostream
 *  This is a Standard C++ Library header.
 */

//
// ISO C++ 14882: 27.3  Standard iostream objects
//

#ifndef _GLIBCXX_IOSTREAM
#define _GLIBCXX_IOSTREAM 1

#ifdef _GLIBCXX_SYSHDR
#pragma GCC system_header
#endif

#include <bits/requires_hosted.h> // iostreams

#include <bits/c++config.h>
#include <ostream>
#include <istream>

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**
   *  @name Standard Stream Objects
   *
   *  The `<iostream>` header declares the eight *standard stream objects*.
   *  For other declarations, see
   *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/io.html
   *  and the @link iosfwd I/O forward declarations @endlink
   *
   *  They are required by default to cooperate with the global C
   *  library's `FILE` streams, and to be available during program
   *  startup and termination. For more information, see the section of the
   *  manual linked to above.
  */
  ///@{
  extern istream cin;		///< Linked to standard input
  extern ostream cout;		///< Linked to standard output
  extern ostream cerr;		///< Linked to standard error (unbuffered)
  extern ostream clog;		///< Linked to standard error (buffered)

#ifdef _GLIBCXX_USE_WCHAR_T
  extern wistream wcin;		///< Linked to standard input
  extern wostream wcout;	///< Linked to standard output
  extern wostream wcerr;	///< Linked to standard error (unbuffered)
  extern wostream wclog;	///< Linked to standard error (buffered)
#endif
  ///@}

  // For construction of filebuffers for cout, cin, cerr, clog et. al.
  // When the init_priority attribute is usable, we do this initialization
  // in the compiled library instead (src/c++98/globals_io.cc).
#if !(_GLIBCXX_USE_INIT_PRIORITY_ATTRIBUTE \
      && __has_attribute(__init_priority__))
  static ios_base::Init __ioinit;
#elif defined(_GLIBCXX_SYMVER_GNU) && defined(__ELF__)
  __extension__ __asm (".globl _ZSt21ios_base_library_initv");
#endif

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#endif /* _GLIBCXX_IOSTREAM */