The C and C++ Include Header Files

/usr/include/c++/11/iosfwd


$ cat -n /usr/include/c++/11/iosfwd

     1	// <iosfwd> Forward declarations -*- C++ -*-
     2	
     3	// Copyright (C) 1997-2021 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/iosfwd
    26	 *  This is a Standard C++ Library header.
    27	 */
    28	
    29	//
    30	// ISO C++ 14882: 27.2  Forward declarations
    31	//
    32	
    33	#ifndef _GLIBCXX_IOSFWD
    34	#define _GLIBCXX_IOSFWD 1
    35	
    36	#pragma GCC system_header
    37	
    38	#include <bits/c++config.h>
    39	#include <bits/stringfwd.h> 	// For string forward declarations.
    40	#include <bits/postypes.h>
    41	
    42	namespace std _GLIBCXX_VISIBILITY(default)
    43	{
    44	_GLIBCXX_BEGIN_NAMESPACE_VERSION
    45	
    46	  /**
    47	   *  @defgroup io I/O
    48	   *
    49	   *  Nearly all of the I/O classes are parameterized on the type of
    50	   *  characters they read and write.  (The major exception is ios_base at
    51	   *  the top of the hierarchy.)  This is a change from pre-Standard
    52	   *  streams, which were not templates.
    53	   *
    54	   *  For ease of use and compatibility, all of the basic_* I/O-related
    55	   *  classes are given typedef names for both of the builtin character
    56	   *  widths (wide and narrow).  The typedefs are the same as the
    57	   *  pre-Standard names, for example:
    58	   *
    59	   *  @code
    60	   *     typedef basic_ifstream<char>  ifstream;
    61	   *  @endcode
    62	   *
    63	   *  Because properly forward-declaring these classes can be difficult, you
    64	   *  should not do it yourself.  Instead, include the <iosfwd>
    65	   *  header, which contains only declarations of all the I/O classes as
    66	   *  well as the typedefs.  Trying to forward-declare the typedefs
    67	   *  themselves (e.g., <code>class ostream;</code>) is not valid ISO C++.
    68	   *
    69	   *  For more specific declarations, see
    70	   *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/io.html#std.io.objects
    71	   *
    72	   *  @{
    73	  */
    74	  class ios_base;
    75	
    76	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
    77	    class basic_ios;
    78	
    79	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
    80	    class basic_streambuf;
    81	
    82	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
    83	    class basic_istream;
    84	
    85	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
    86	    class basic_ostream;
    87	
    88	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
    89	    class basic_iostream;
    90	
    91	
    92	_GLIBCXX_BEGIN_NAMESPACE_CXX11
    93	
    94	  template<typename _CharT, typename _Traits = char_traits<_CharT>,
    95		    typename _Alloc = allocator<_CharT> >
    96	    class basic_stringbuf;
    97	
    98	  template<typename _CharT, typename _Traits = char_traits<_CharT>,
    99		   typename _Alloc = allocator<_CharT> >
   100	    class basic_istringstream;
   101	
   102	  template<typename _CharT, typename _Traits = char_traits<_CharT>,
   103		   typename _Alloc = allocator<_CharT> >
   104	    class basic_ostringstream;
   105	
   106	  template<typename _CharT, typename _Traits = char_traits<_CharT>,
   107		   typename _Alloc = allocator<_CharT> >
   108	    class basic_stringstream;
   109	
   110	_GLIBCXX_END_NAMESPACE_CXX11
   111	
   112	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
   113	    class basic_filebuf;
   114	
   115	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
   116	    class basic_ifstream;
   117	
   118	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
   119	    class basic_ofstream;
   120	
   121	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
   122	    class basic_fstream;
   123	
   124	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
   125	    class istreambuf_iterator;
   126	
   127	  template<typename _CharT, typename _Traits = char_traits<_CharT> >
   128	    class ostreambuf_iterator;
   129	
   130	
   131	  /// Base class for @c char streams.
   132	  typedef basic_ios<char> 		ios;
   133	
   134	  /// Base class for @c char buffers.
   135	  typedef basic_streambuf<char> 	streambuf;
   136	
   137	  /// Base class for @c char input streams.
   138	  typedef basic_istream<char> 		istream;
   139	
   140	  /// Base class for @c char output streams.
   141	  typedef basic_ostream<char> 		ostream;
   142	
   143	  /// Base class for @c char mixed input and output streams.
   144	  typedef basic_iostream<char> 		iostream;
   145	
   146	  /// Class for @c char memory buffers.
   147	  typedef basic_stringbuf<char> 	stringbuf;
   148	
   149	  /// Class for @c char input memory streams.
   150	  typedef basic_istringstream<char> 	istringstream;
   151	
   152	  /// Class for @c char output memory streams.
   153	  typedef basic_ostringstream<char> 	ostringstream;
   154	
   155	  /// Class for @c char mixed input and output memory streams.
   156	  typedef basic_stringstream<char> 	stringstream;
   157	
   158	  /// Class for @c char file buffers.
   159	  typedef basic_filebuf<char> 		filebuf;
   160	
   161	  /// Class for @c char input file streams.
   162	  typedef basic_ifstream<char> 		ifstream;
   163	
   164	  /// Class for @c char output file streams.
   165	  typedef basic_ofstream<char> 		ofstream;
   166	
   167	  /// Class for @c char mixed input and output file streams.
   168	  typedef basic_fstream<char> 		fstream;
   169	
   170	#ifdef _GLIBCXX_USE_WCHAR_T
   171	  /// Base class for @c wchar_t streams.
   172	  typedef basic_ios<wchar_t> 		wios;
   173	
   174	  /// Base class for @c wchar_t buffers.
   175	  typedef basic_streambuf<wchar_t> 	wstreambuf;
   176	
   177	  /// Base class for @c wchar_t input streams.
   178	  typedef basic_istream<wchar_t> 	wistream;
   179	
   180	  /// Base class for @c wchar_t output streams.
   181	  typedef basic_ostream<wchar_t> 	wostream;
   182	
   183	  /// Base class for @c wchar_t mixed input and output streams.
   184	  typedef basic_iostream<wchar_t> 	wiostream;
   185	
   186	  /// Class for @c wchar_t memory buffers.
   187	  typedef basic_stringbuf<wchar_t> 	wstringbuf;
   188	
   189	  /// Class for @c wchar_t input memory streams.
   190	  typedef basic_istringstream<wchar_t> 	wistringstream;
   191	
   192	  /// Class for @c wchar_t output memory streams.
   193	  typedef basic_ostringstream<wchar_t> 	wostringstream;
   194	
   195	  /// Class for @c wchar_t mixed input and output memory streams.
   196	  typedef basic_stringstream<wchar_t> 	wstringstream;
   197	
   198	  /// Class for @c wchar_t file buffers.
   199	  typedef basic_filebuf<wchar_t> 	wfilebuf;
   200	
   201	  /// Class for @c wchar_t input file streams.
   202	  typedef basic_ifstream<wchar_t> 	wifstream;
   203	
   204	  /// Class for @c wchar_t output file streams.
   205	  typedef basic_ofstream<wchar_t> 	wofstream;
   206	
   207	  /// Class for @c wchar_t mixed input and output file streams.
   208	  typedef basic_fstream<wchar_t> 	wfstream;
   209	#endif
   210	
   211	#if __cplusplus >= 202002L && _GLIBCXX_USE_CXX11_ABI
   212	  template<typename _CharT, typename _Traits = char_traits<_CharT>,
   213	           typename _Allocator = allocator<_CharT>>
   214	    class basic_syncbuf;
   215	  template<typename _CharT, typename _Traits = char_traits<_CharT>,
   216	           typename _Allocator = allocator<_CharT>>
   217	    class basic_osyncstream;
   218	
   219	  using syncbuf = basic_syncbuf<char>;
   220	  using osyncstream = basic_osyncstream<char>;
   221	
   222	#ifdef _GLIBCXX_USE_WCHAR_T
   223	  using wsyncbuf = basic_syncbuf<wchar_t>;
   224	  using wosyncstream = basic_osyncstream<wchar_t>;
   225	#endif
   226	#endif // C++20 && CXX11_ABI
   227	
   228	  /** @}  */
   229	
   230	_GLIBCXX_END_NAMESPACE_VERSION
   231	} // namespace
   232	
   233	#endif /* _GLIBCXX_IOSFWD */