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The C and C++ Include Header Files

cat -n /usr/include/c++/15/bits/basic_ios.tcc

     1	// basic_ios member functions -*- C++ -*-
     2	
     3	// Copyright (C) 1999-2025 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/basic_ios.tcc
    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	#ifndef _BASIC_IOS_TCC
    31	#define _BASIC_IOS_TCC 1
    32	
    33	#ifdef _GLIBCXX_SYSHDR
    34	#pragma GCC system_header
    35	#endif
    36	
    37	#pragma GCC diagnostic push
    38	#pragma GCC diagnostic ignored "-Wc++11-extensions" // extern template
    39	
    40	namespace std _GLIBCXX_VISIBILITY(default)
    41	{
    42	_GLIBCXX_BEGIN_NAMESPACE_VERSION
    43	
    44	  template<typename _CharT, typename _Traits>
    45	    void
    46	    basic_ios<_CharT, _Traits>::clear(iostate __state)
    47	    {
    48	      if (this->rdbuf())
    49		_M_streambuf_state = __state;
    50	      else
    51		_M_streambuf_state = __state | badbit;
    52	      if (this->exceptions() & this->rdstate())
    53		__throw_ios_failure(__N("basic_ios::clear"));
    54	    }
    55	
    56	  template<typename _CharT, typename _Traits>
    57	    basic_streambuf<_CharT, _Traits>*
    58	    basic_ios<_CharT, _Traits>::rdbuf(basic_streambuf<_CharT, _Traits>* __sb)
    59	    {
    60	      basic_streambuf<_CharT, _Traits>* __old = _M_streambuf;
    61	      _M_streambuf = __sb;
    62	      this->clear();
    63	      return __old;
    64	    }
    65	
    66	  template<typename _CharT, typename _Traits>
    67	    basic_ios<_CharT, _Traits>&
    68	    basic_ios<_CharT, _Traits>::copyfmt(const basic_ios& __rhs)
    69	    {
    70	      // _GLIBCXX_RESOLVE_LIB_DEFECTS
    71	      // 292. effects of a.copyfmt (a)
    72	      if (this != std::__addressof(__rhs))
    73		{
    74		  // Per 27.1.1, do not call imbue, yet must trash all caches
    75		  // associated with imbue()
    76	
    77		  // Alloc any new word array first, so if it fails we have "rollback".
    78		  _Words* __words = (__rhs._M_word_size <= _S_local_word_size) ?
    79		                     _M_local_word : new _Words[__rhs._M_word_size];
    80	
    81		  // Bump refs before doing callbacks, for safety.
    82		  _Callback_list* __cb = __rhs._M_callbacks;
    83		  if (__cb)
    84		    __cb->_M_add_reference();
    85		  _M_call_callbacks(erase_event);
    86		  if (_M_word != _M_local_word)
    87		    {
    88		      delete [] _M_word;
    89		      _M_word = 0;
    90		    }
    91		  _M_dispose_callbacks();
    92	
    93		  // NB: Don't want any added during above.
    94		  _M_callbacks = __cb;
    95		  for (int __i = 0; __i < __rhs._M_word_size; ++__i)
    96		    __words[__i] = __rhs._M_word[__i];
    97		  _M_word = __words;
    98		  _M_word_size = __rhs._M_word_size;
    99	
   100		  this->flags(__rhs.flags());
   101		  this->width(__rhs.width());
   102		  this->precision(__rhs.precision());
   103		  this->tie(__rhs.tie());
   104		  this->fill(__rhs.fill());
   105		  _M_ios_locale = __rhs.getloc();
   106		  _M_cache_locale(_M_ios_locale);
   107	
   108		  _M_call_callbacks(copyfmt_event);
   109	
   110		  // The next is required to be the last assignment.
   111		  this->exceptions(__rhs.exceptions());
   112		}
   113	      return *this;
   114	    }
   115	
   116	  // Locales:
   117	  template<typename _CharT, typename _Traits>
   118	    locale
   119	    basic_ios<_CharT, _Traits>::imbue(const locale& __loc)
   120	    {
   121	      locale __old(this->getloc());
   122	      ios_base::imbue(__loc);
   123	      _M_cache_locale(__loc);
   124	      if (this->rdbuf() != 0)
   125		this->rdbuf()->pubimbue(__loc);
   126	      return __old;
   127	    }
   128	
   129	  template<typename _CharT, typename _Traits>
   130	    void
   131	    basic_ios<_CharT, _Traits>::init(basic_streambuf<_CharT, _Traits>* __sb)
   132	    {
   133	      // NB: This may be called more than once on the same object.
   134	      ios_base::_M_init();
   135	
   136	      // Cache locale data and specific facets used by iostreams.
   137	      _M_cache_locale(_M_ios_locale);
   138	
   139	      // NB: The 27.4.4.1 Postconditions Table specifies requirements
   140	      // after basic_ios::init() has been called. As part of this,
   141	      // fill() must return widen(' ') any time after init() has been
   142	      // called, which needs an imbued ctype facet of char_type to
   143	      // return without throwing an exception. Unfortunately,
   144	      // ctype<char_type> is not necessarily a required facet, so
   145	      // streams with char_type != [char, wchar_t] will not have it by
   146	      // default. If the ctype<char_type> facet is available now,
   147	      // _M_fill is set here, but otherwise no fill character will be
   148	      // cached and a call to fill() will check for the facet again later
   149	      // (and will throw if the facet is still not present). This way
   150	      // unformatted input and output with non-required basic_ios
   151	      // instantiations is possible even without imbuing the expected
   152	      // ctype<char_type> facet.
   153	      if (_M_ctype)
   154		{
   155		  _M_fill = _M_ctype->widen(' ');
   156		  _M_fill_init = true;
   157		}
   158	      else
   159		_M_fill_init = false;
   160	
   161	      _M_tie = 0;
   162	      _M_exception = goodbit;
   163	      _M_streambuf = __sb;
   164	      _M_streambuf_state = __sb ? goodbit : badbit;
   165	    }
   166	
   167	  template<typename _CharT, typename _Traits>
   168	    void
   169	    basic_ios<_CharT, _Traits>::_M_cache_locale(const locale& __loc)
   170	    {
   171	      _M_ctype = std::__try_use_facet<__ctype_type>(__loc);
   172	      _M_num_put = std::__try_use_facet<__num_put_type>(__loc);
   173	      _M_num_get = std::__try_use_facet<__num_get_type>(__loc);
   174	    }
   175	
   176	  // Inhibit implicit instantiations for required instantiations,
   177	  // which are defined via explicit instantiations elsewhere.
   178	#if _GLIBCXX_EXTERN_TEMPLATE
   179	  extern template class basic_ios<char>;
   180	
   181	#ifdef _GLIBCXX_USE_WCHAR_T
   182	  extern template class basic_ios<wchar_t>;
   183	#endif
   184	#endif
   185	
   186	_GLIBCXX_END_NAMESPACE_VERSION
   187	} // namespace std
   188	
   189	#pragma GCC diagnostic pop
   190	#endif