// File based streams -*- C++ -*-
	
	// Copyright (C) 1997-2013 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/fstream
	 *  This is a Standard C++ Library header.
	 */
	
	//
	// ISO C++ 14882: 27.8  File-based streams
	//
	
	#ifndef _GLIBCXX_FSTREAM
	#define _GLIBCXX_FSTREAM 1
	
	#pragma GCC system_header
	
	#include <istream>
	#include <ostream>
	#include <bits/codecvt.h>
	#include <cstdio>             // For BUFSIZ
	#include <bits/basic_file.h>  // For __basic_file, __c_lock
	#if __cplusplus >= 201103L
	#include <string>             // For std::string overloads.
	#endif
	
	namespace std _GLIBCXX_VISIBILITY(default)
	{
	_GLIBCXX_BEGIN_NAMESPACE_VERSION
	
	  // [27.8.1.1] template class basic_filebuf
	  /**
	   *  @brief  The actual work of input and output (for files).
	   *  @ingroup io
	   *
	   *  @tparam _CharT  Type of character stream.
	   *  @tparam _Traits  Traits for character type, defaults to
	   *                   char_traits<_CharT>.
	   *
	   *  This class associates both its input and output sequence with an
	   *  external disk file, and maintains a joint file position for both
	   *  sequences.  Many of its semantics are described in terms of similar
	   *  behavior in the Standard C Library's @c FILE streams.
	   *
	   *  Requirements on traits_type, specific to this class:
	   *  - traits_type::pos_type must be fpos<traits_type::state_type>
	   *  - traits_type::off_type must be streamoff
	   *  - traits_type::state_type must be Assignable and DefaultConstructible,
	   *  - traits_type::state_type() must be the initial state for codecvt.
	   */
	  template<typename _CharT, typename _Traits>
	    class basic_filebuf : public basic_streambuf<_CharT, _Traits>
	    {
	    public:
	      // Types:
	      typedef _CharT                     	        char_type;
	      typedef _Traits                    	        traits_type;
	      typedef typename traits_type::int_type 		int_type;
	      typedef typename traits_type::pos_type 		pos_type;
	      typedef typename traits_type::off_type 		off_type;
	
	      typedef basic_streambuf<char_type, traits_type>  	__streambuf_type;
	      typedef basic_filebuf<char_type, traits_type>     __filebuf_type;
	      typedef __basic_file<char>		        __file_type;
	      typedef typename traits_type::state_type          __state_type;
	      typedef codecvt<char_type, char, __state_type>    __codecvt_type;
	
	      friend class ios_base; // For sync_with_stdio.
	
	    protected:
	      // Data Members:
	      // MT lock inherited from libio or other low-level io library.
	      __c_lock          	_M_lock;
	
	      // External buffer.
	      __file_type 		_M_file;
	
	      /// Place to stash in || out || in | out settings for current filebuf.
	      ios_base::openmode 	_M_mode;
	
	      // Beginning state type for codecvt.
	      __state_type 		_M_state_beg;
	
	      // During output, the state that corresponds to pptr(),
	      // during input, the state that corresponds to egptr() and
	      // _M_ext_next.
	      __state_type		_M_state_cur;
	
	      // Not used for output. During input, the state that corresponds
	      // to eback() and _M_ext_buf.
	      __state_type		_M_state_last;
	
	      /// Pointer to the beginning of internal buffer.
	      char_type*		_M_buf; 	
	
	      /**
	       *  Actual size of internal buffer. This number is equal to the size
	       *  of the put area + 1 position, reserved for the overflow char of
	       *  a full area.
	       */
	      size_t			_M_buf_size;
	
	      // Set iff _M_buf is allocated memory from _M_allocate_internal_buffer.
	      bool			_M_buf_allocated;
	
	      /**
	       *  _M_reading == false && _M_writing == false for @b uncommitted mode;
	       *  _M_reading == true for @b read mode;
	       *  _M_writing == true for @b write mode;
	       *
	       *  NB: _M_reading == true && _M_writing == true is unused.
	       */
	      bool                      _M_reading;
	      bool                      _M_writing;
	
	      //@{
	      /**
	       *  Necessary bits for putback buffer management.
	       *
	       *  @note pbacks of over one character are not currently supported.
	       */
	      char_type			_M_pback;
	      char_type*		_M_pback_cur_save;
	      char_type*		_M_pback_end_save;
	      bool			_M_pback_init;
	      //@}
	
	      // Cached codecvt facet.
	      const __codecvt_type* 	_M_codecvt;
	
	      /**
	       *  Buffer for external characters. Used for input when
	       *  codecvt::always_noconv() == false. When valid, this corresponds
	       *  to eback().
	       */
	      char*			_M_ext_buf;
	
	      /**
	       *  Size of buffer held by _M_ext_buf.
	       */
	      streamsize		_M_ext_buf_size;
	
	      /**
	       *  Pointers into the buffer held by _M_ext_buf that delimit a
	       *  subsequence of bytes that have been read but not yet converted.
	       *  When valid, _M_ext_next corresponds to egptr().
	       */
	      const char*		_M_ext_next;
	      char*			_M_ext_end;
	
	      /**
	       *  Initializes pback buffers, and moves normal buffers to safety.
	       *  Assumptions:
	       *  _M_in_cur has already been moved back
	       */
	      void
	      _M_create_pback()
	      {
		if (!_M_pback_init)
		  {
		    _M_pback_cur_save = this->gptr();
		    _M_pback_end_save = this->egptr();
		    this->setg(&_M_pback, &_M_pback, &_M_pback + 1);
		    _M_pback_init = true;
		  }
	      }
	
	      /**
	       *  Deactivates pback buffer contents, and restores normal buffer.
	       *  Assumptions:
	       *  The pback buffer has only moved forward.
	       */
	      void
	      _M_destroy_pback() throw()
	      {
		if (_M_pback_init)
		  {
		    // Length _M_in_cur moved in the pback buffer.
		    _M_pback_cur_save += this->gptr() != this->eback();
		    this->setg(_M_buf, _M_pback_cur_save, _M_pback_end_save);
		    _M_pback_init = false;
		  }
	      }
	
	    public:
	      // Constructors/destructor:
	      /**
	       *  @brief  Does not open any files.
	       *
	       *  The default constructor initializes the parent class using its
	       *  own default ctor.
	       */
	      basic_filebuf();
	
	      /**
	       *  @brief  The destructor closes the file first.
	       */
	      virtual
	      ~basic_filebuf()
	      { this->close(); }
	
	      // Members:
	      /**
	       *  @brief  Returns true if the external file is open.
	       */
	      bool
	      is_open() const throw()
	      { return _M_file.is_open(); }
	
	      /**
	       *  @brief  Opens an external file.
	       *  @param  __s  The name of the file.
	       *  @param  __mode  The open mode flags.
	       *  @return  @c this on success, NULL on failure
	       *
	       *  If a file is already open, this function immediately fails.
	       *  Otherwise it tries to open the file named @a __s using the flags
	       *  given in @a __mode.
	       *
	       *  Table 92, adapted here, gives the relation between openmode
	       *  combinations and the equivalent fopen() flags.
	       *  (NB: lines app, in|out|app, in|app, binary|app, binary|in|out|app,
	       *  and binary|in|app per DR 596)
	       *  +---------------------------------------------------------+
	       *  | ios_base Flag combination            stdio equivalent   |
	       *  |binary  in  out  trunc  app                              |
	       *  +---------------------------------------------------------+
	       *  |             +                        w                  |
	       *  |             +           +            a                  |
	       *  |                         +            a                  |
	       *  |             +     +                  w                  |
	       *  |         +                            r                  |
	       *  |         +   +                        r+                 |
	       *  |         +   +     +                  w+                 |
	       *  |         +   +           +            a+                 |
	       *  |         +               +            a+                 |
	       *  +---------------------------------------------------------+
	       *  |   +         +                        wb                 |
	       *  |   +         +           +            ab                 |
	       *  |   +                     +            ab                 |
	       *  |   +         +     +                  wb                 |
	       *  |   +     +                            rb                 |
	       *  |   +     +   +                        r+b                |
	       *  |   +     +   +     +                  w+b                |
	       *  |   +     +   +           +            a+b                |
	       *  |   +     +               +            a+b                |
	       *  +---------------------------------------------------------+
	       */
	      __filebuf_type*
	      open(const char* __s, ios_base::openmode __mode);
	
	#if __cplusplus >= 201103L
	      /**
	       *  @brief  Opens an external file.
	       *  @param  __s  The name of the file.
	       *  @param  __mode  The open mode flags.
	       *  @return  @c this on success, NULL on failure
	       */
	      __filebuf_type*
	      open(const std::string& __s, ios_base::openmode __mode)
	      { return open(__s.c_str(), __mode); }
	#endif
	
	      /**
	       *  @brief  Closes the currently associated file.
	       *  @return  @c this on success, NULL on failure
	       *
	       *  If no file is currently open, this function immediately fails.
	       *
	       *  If a <em>put buffer area</em> exists, @c overflow(eof) is
	       *  called to flush all the characters.  The file is then
	       *  closed.
	       *
	       *  If any operations fail, this function also fails.
	       */
	      __filebuf_type*
	      close();
	
	    protected:
	      void
	      _M_allocate_internal_buffer();
	
	      void
	      _M_destroy_internal_buffer() throw();
	
	      // [27.8.1.4] overridden virtual functions
	      virtual streamsize
	      showmanyc();
	
	      // Stroustrup, 1998, p. 628
	      // underflow() and uflow() functions are called to get the next
	      // character from the real input source when the buffer is empty.
	      // Buffered input uses underflow()
	
	      virtual int_type
	      underflow();
	
	      virtual int_type
	      pbackfail(int_type __c = _Traits::eof());
	
	      // Stroustrup, 1998, p 648
	      // The overflow() function is called to transfer characters to the
	      // real output destination when the buffer is full. A call to
	      // overflow(c) outputs the contents of the buffer plus the
	      // character c.
	      // 27.5.2.4.5
	      // Consume some sequence of the characters in the pending sequence.
	      virtual int_type
	      overflow(int_type __c = _Traits::eof());
	
	      // Convert internal byte sequence to external, char-based
	      // sequence via codecvt.
	      bool
	      _M_convert_to_external(char_type*, streamsize);
	
	      /**
	       *  @brief  Manipulates the buffer.
	       *  @param  __s  Pointer to a buffer area.
	       *  @param  __n  Size of @a __s.
	       *  @return  @c this
	       *
	       *  If no file has been opened, and both @a __s and @a __n are zero, then
	       *  the stream becomes unbuffered.  Otherwise, @c __s is used as a
	       *  buffer; see
	       *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html
	       *  for more.
	       */
	      virtual __streambuf_type*
	      setbuf(char_type* __s, streamsize __n);
	
	      virtual pos_type
	      seekoff(off_type __off, ios_base::seekdir __way,
		      ios_base::openmode __mode = ios_base::in | ios_base::out);
	
	      virtual pos_type
	      seekpos(pos_type __pos,
		      ios_base::openmode __mode = ios_base::in | ios_base::out);
	
	      // Common code for seekoff, seekpos, and overflow
	      pos_type
	      _M_seek(off_type __off, ios_base::seekdir __way, __state_type __state);
	      
	      int
	      _M_get_ext_pos(__state_type &__state);
	
	      virtual int
	      sync();
	
	      virtual void
	      imbue(const locale& __loc);
	
	      virtual streamsize
	      xsgetn(char_type* __s, streamsize __n);
	
	      virtual streamsize
	      xsputn(const char_type* __s, streamsize __n);
	
	      // Flushes output buffer, then writes unshift sequence.
	      bool
	      _M_terminate_output();
	
	      /**
	       *  This function sets the pointers of the internal buffer, both get
	       *  and put areas. Typically:
	       *
	       *   __off == egptr() - eback() upon underflow/uflow (@b read mode);
	       *   __off == 0 upon overflow (@b write mode);
	       *   __off == -1 upon open, setbuf, seekoff/pos (@b uncommitted mode).
	       *
	       *  NB: epptr() - pbase() == _M_buf_size - 1, since _M_buf_size
	       *  reflects the actual allocated memory and the last cell is reserved
	       *  for the overflow char of a full put area.
	       */
	      void
	      _M_set_buffer(streamsize __off)
	      {
	 	const bool __testin = _M_mode & ios_base::in;
	 	const bool __testout = _M_mode & ios_base::out;
		
		if (__testin && __off > 0)
		  this->setg(_M_buf, _M_buf, _M_buf + __off);
		else
		  this->setg(_M_buf, _M_buf, _M_buf);
	
		if (__testout && __off == 0 && _M_buf_size > 1 )
		  this->setp(_M_buf, _M_buf + _M_buf_size - 1);
		else
		  this->setp(0, 0);
	      }
	    };
	
	  // [27.8.1.5] Template class basic_ifstream
	  /**
	   *  @brief  Controlling input for files.
	   *  @ingroup io
	   *
	   *  @tparam _CharT  Type of character stream.
	   *  @tparam _Traits  Traits for character type, defaults to
	   *                   char_traits<_CharT>.
	   *
	   *  This class supports reading from named files, using the inherited
	   *  functions from std::basic_istream.  To control the associated
	   *  sequence, an instance of std::basic_filebuf is used, which this page
	   *  refers to as @c sb.
	   */
	  template<typename _CharT, typename _Traits>
	    class basic_ifstream : public basic_istream<_CharT, _Traits>
	    {
	    public:
	      // Types:
	      typedef _CharT 					char_type;
	      typedef _Traits 					traits_type;
	      typedef typename traits_type::int_type 		int_type;
	      typedef typename traits_type::pos_type 		pos_type;
	      typedef typename traits_type::off_type 		off_type;
	
	      // Non-standard types:
	      typedef basic_filebuf<char_type, traits_type> 	__filebuf_type;
	      typedef basic_istream<char_type, traits_type>	__istream_type;
	
	    private:
	      __filebuf_type	_M_filebuf;
	
	    public:
	      // Constructors/Destructors:
	      /**
	       *  @brief  Default constructor.
	       *
	       *  Initializes @c sb using its default constructor, and passes
	       *  @c &sb to the base class initializer.  Does not open any files
	       *  (you haven't given it a filename to open).
	       */
	      basic_ifstream() : __istream_type(), _M_filebuf()
	      { this->init(&_M_filebuf); }
	
	      /**
	       *  @brief  Create an input file stream.
	       *  @param  __s  Null terminated string specifying the filename.
	       *  @param  __mode  Open file in specified mode (see std::ios_base).
	       *
	       *  @c ios_base::in is automatically included in @a __mode.
	       *
	       *  Tip:  When using std::string to hold the filename, you must use
	       *  .c_str() before passing it to this constructor.
	       */
	      explicit
	      basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in)
	      : __istream_type(), _M_filebuf()
	      {
		this->init(&_M_filebuf);
		this->open(__s, __mode);
	      }
	
	#if __cplusplus >= 201103L
	      /**
	       *  @brief  Create an input file stream.
	       *  @param  __s  std::string specifying the filename.
	       *  @param  __mode  Open file in specified mode (see std::ios_base).
	       *
	       *  @c ios_base::in is automatically included in @a __mode.
	       */
	      explicit
	      basic_ifstream(const std::string& __s,
			     ios_base::openmode __mode = ios_base::in)
	      : __istream_type(), _M_filebuf()
	      {
		this->init(&_M_filebuf);
		this->open(__s, __mode);
	      }
	#endif
	
	      /**
	       *  @brief  The destructor does nothing.
	       *
	       *  The file is closed by the filebuf object, not the formatting
	       *  stream.
	       */
	      ~basic_ifstream()
	      { }
	
	      // Members:
	      /**
	       *  @brief  Accessing the underlying buffer.
	       *  @return  The current basic_filebuf buffer.
	       *
	       *  This hides both signatures of std::basic_ios::rdbuf().
	       */
	      __filebuf_type*
	      rdbuf() const
	      { return const_cast<__filebuf_type*>(&_M_filebuf); }
	
	      /**
	       *  @brief  Wrapper to test for an open file.
	       *  @return  @c rdbuf()->is_open()
	       */
	      bool
	      is_open()
	      { return _M_filebuf.is_open(); }
	
	      // _GLIBCXX_RESOLVE_LIB_DEFECTS
	      // 365. Lack of const-qualification in clause 27
	      bool
	      is_open() const
	      { return _M_filebuf.is_open(); }
	
	      /**
	       *  @brief  Opens an external file.
	       *  @param  __s  The name of the file.
	       *  @param  __mode  The open mode flags.
	       *
	       *  Calls @c std::basic_filebuf::open(s,__mode|in).  If that function
	       *  fails, @c failbit is set in the stream's error state.
	       *
	       *  Tip:  When using std::string to hold the filename, you must use
	       *  .c_str() before passing it to this constructor.
	       */
	      void
	      open(const char* __s, ios_base::openmode __mode = ios_base::in)
	      {
		if (!_M_filebuf.open(__s, __mode | ios_base::in))
		  this->setstate(ios_base::failbit);
		else
		  // _GLIBCXX_RESOLVE_LIB_DEFECTS
		  // 409. Closing an fstream should clear error state
		  this->clear();
	      }
	
	#if __cplusplus >= 201103L
	      /**
	       *  @brief  Opens an external file.
	       *  @param  __s  The name of the file.
	       *  @param  __mode  The open mode flags.
	       *
	       *  Calls @c std::basic_filebuf::open(__s,__mode|in).  If that function
	       *  fails, @c failbit is set in the stream's error state.
	       */
	      void
	      open(const std::string& __s, ios_base::openmode __mode = ios_base::in)
	      {
		if (!_M_filebuf.open(__s, __mode | ios_base::in))
		  this->setstate(ios_base::failbit);
		else
		  // _GLIBCXX_RESOLVE_LIB_DEFECTS
		  // 409. Closing an fstream should clear error state
		  this->clear();
	      }
	#endif
	
	      /**
	       *  @brief  Close the file.
	       *
	       *  Calls @c std::basic_filebuf::close().  If that function
	       *  fails, @c failbit is set in the stream's error state.
	       */
	      void
	      close()
	      {
		if (!_M_filebuf.close())
		  this->setstate(ios_base::failbit);
	      }
	    };
	
	
	  // [27.8.1.8] Template class basic_ofstream
	  /**
	   *  @brief  Controlling output for files.
	   *  @ingroup io
	   *
	   *  @tparam _CharT  Type of character stream.
	   *  @tparam _Traits  Traits for character type, defaults to
	   *                   char_traits<_CharT>.
	   *
	   *  This class supports reading from named files, using the inherited
	   *  functions from std::basic_ostream.  To control the associated
	   *  sequence, an instance of std::basic_filebuf is used, which this page
	   *  refers to as @c sb.
	   */
	  template<typename _CharT, typename _Traits>
	    class basic_ofstream : public basic_ostream<_CharT,_Traits>
	    {
	    public:
	      // Types:
	      typedef _CharT 					char_type;
	      typedef _Traits 					traits_type;
	      typedef typename traits_type::int_type 		int_type;
	      typedef typename traits_type::pos_type 		pos_type;
	      typedef typename traits_type::off_type 		off_type;
	
	      // Non-standard types:
	      typedef basic_filebuf<char_type, traits_type> 	__filebuf_type;
	      typedef basic_ostream<char_type, traits_type>	__ostream_type;
	
	    private:
	      __filebuf_type	_M_filebuf;
	
	    public:
	      // Constructors:
	      /**
	       *  @brief  Default constructor.
	       *
	       *  Initializes @c sb using its default constructor, and passes
	       *  @c &sb to the base class initializer.  Does not open any files
	       *  (you haven't given it a filename to open).
	       */
	      basic_ofstream(): __ostream_type(), _M_filebuf()
	      { this->init(&_M_filebuf); }
	
	      /**
	       *  @brief  Create an output file stream.
	       *  @param  __s  Null terminated string specifying the filename.
	       *  @param  __mode  Open file in specified mode (see std::ios_base).
	       *
	       *  @c ios_base::out | @c ios_base::trunc is automatically included in
	       *  @a __mode.
	       *
	       *  Tip:  When using std::string to hold the filename, you must use
	       *  .c_str() before passing it to this constructor.
	       */
	      explicit
	      basic_ofstream(const char* __s,
			     ios_base::openmode __mode = ios_base::out|ios_base::trunc)
	      : __ostream_type(), _M_filebuf()
	      {
		this->init(&_M_filebuf);
		this->open(__s, __mode);
	      }
	
	#if __cplusplus >= 201103L
	      /**
	       *  @brief  Create an output file stream.
	       *  @param  __s  std::string specifying the filename.
	       *  @param  __mode  Open file in specified mode (see std::ios_base).
	       *
	       *  @c ios_base::out | @c ios_base::trunc is automatically included in
	       *  @a __mode.
	       */
	      explicit
	      basic_ofstream(const std::string& __s,
			     ios_base::openmode __mode = ios_base::out|ios_base::trunc)
	      : __ostream_type(), _M_filebuf()
	      {
		this->init(&_M_filebuf);
		this->open(__s, __mode);
	      }
	#endif
	
	      /**
	       *  @brief  The destructor does nothing.
	       *
	       *  The file is closed by the filebuf object, not the formatting
	       *  stream.
	       */
	      ~basic_ofstream()
	      { }
	
	      // Members:
	      /**
	       *  @brief  Accessing the underlying buffer.
	       *  @return  The current basic_filebuf buffer.
	       *
	       *  This hides both signatures of std::basic_ios::rdbuf().
	       */
	      __filebuf_type*
	      rdbuf() const
	      { return const_cast<__filebuf_type*>(&_M_filebuf); }
	
	      /**
	       *  @brief  Wrapper to test for an open file.
	       *  @return  @c rdbuf()->is_open()
	       */
	      bool
	      is_open()
	      { return _M_filebuf.is_open(); }
	
	      // _GLIBCXX_RESOLVE_LIB_DEFECTS
	      // 365. Lack of const-qualification in clause 27
	      bool
	      is_open() const
	      { return _M_filebuf.is_open(); }
	
	      /**
	       *  @brief  Opens an external file.
	       *  @param  __s  The name of the file.
	       *  @param  __mode  The open mode flags.
	       *
	       *  Calls @c std::basic_filebuf::open(__s,__mode|out|trunc).  If that
	       *  function fails, @c failbit is set in the stream's error state.
	       *
	       *  Tip:  When using std::string to hold the filename, you must use
	       *  .c_str() before passing it to this constructor.
	       */
	      void
	      open(const char* __s,
		   ios_base::openmode __mode = ios_base::out | ios_base::trunc)
	      {
		if (!_M_filebuf.open(__s, __mode | ios_base::out))
		  this->setstate(ios_base::failbit);
		else
		  // _GLIBCXX_RESOLVE_LIB_DEFECTS
		  // 409. Closing an fstream should clear error state
		  this->clear();
	      }
	
	#if __cplusplus >= 201103L
	      /**
	       *  @brief  Opens an external file.
	       *  @param  __s  The name of the file.
	       *  @param  __mode  The open mode flags.
	       *
	       *  Calls @c std::basic_filebuf::open(s,mode|out|trunc).  If that
	       *  function fails, @c failbit is set in the stream's error state.
	       */
	      void
	      open(const std::string& __s,
		   ios_base::openmode __mode = ios_base::out | ios_base::trunc)
	      {
		if (!_M_filebuf.open(__s, __mode | ios_base::out))
		  this->setstate(ios_base::failbit);
		else
		  // _GLIBCXX_RESOLVE_LIB_DEFECTS
		  // 409. Closing an fstream should clear error state
		  this->clear();
	      }
	#endif
	
	      /**
	       *  @brief  Close the file.
	       *
	       *  Calls @c std::basic_filebuf::close().  If that function
	       *  fails, @c failbit is set in the stream's error state.
	       */
	      void
	      close()
	      {
		if (!_M_filebuf.close())
		  this->setstate(ios_base::failbit);
	      }
	    };
	
	
	  // [27.8.1.11] Template class basic_fstream
	  /**
	   *  @brief  Controlling input and output for files.
	   *  @ingroup io
	   *
	   *  @tparam _CharT  Type of character stream.
	   *  @tparam _Traits  Traits for character type, defaults to
	   *                   char_traits<_CharT>.
	   *
	   *  This class supports reading from and writing to named files, using
	   *  the inherited functions from std::basic_iostream.  To control the
	   *  associated sequence, an instance of std::basic_filebuf is used, which
	   *  this page refers to as @c sb.
	   */
	  template<typename _CharT, typename _Traits>
	    class basic_fstream : public basic_iostream<_CharT, _Traits>
	    {
	    public:
	      // Types:
	      typedef _CharT 					char_type;
	      typedef _Traits 					traits_type;
	      typedef typename traits_type::int_type 		int_type;
	      typedef typename traits_type::pos_type 		pos_type;
	      typedef typename traits_type::off_type 		off_type;
	
	      // Non-standard types:
	      typedef basic_filebuf<char_type, traits_type> 	__filebuf_type;
	      typedef basic_ios<char_type, traits_type>		__ios_type;
	      typedef basic_iostream<char_type, traits_type>	__iostream_type;
	
	    private:
	      __filebuf_type	_M_filebuf;
	
	    public:
	      // Constructors/destructor:
	      /**
	       *  @brief  Default constructor.
	       *
	       *  Initializes @c sb using its default constructor, and passes
	       *  @c &sb to the base class initializer.  Does not open any files
	       *  (you haven't given it a filename to open).
	       */
	      basic_fstream()
	      : __iostream_type(), _M_filebuf()
	      { this->init(&_M_filebuf); }
	
	      /**
	       *  @brief  Create an input/output file stream.
	       *  @param  __s  Null terminated string specifying the filename.
	       *  @param  __mode  Open file in specified mode (see std::ios_base).
	       *
	       *  Tip:  When using std::string to hold the filename, you must use
	       *  .c_str() before passing it to this constructor.
	       */
	      explicit
	      basic_fstream(const char* __s,
			    ios_base::openmode __mode = ios_base::in | ios_base::out)
	      : __iostream_type(0), _M_filebuf()
	      {
		this->init(&_M_filebuf);
		this->open(__s, __mode);
	      }
	
	#if __cplusplus >= 201103L
	      /**
	       *  @brief  Create an input/output file stream.
	       *  @param  __s  Null terminated string specifying the filename.
	       *  @param  __mode  Open file in specified mode (see std::ios_base).
	       */
	      explicit
	      basic_fstream(const std::string& __s,
			    ios_base::openmode __mode = ios_base::in | ios_base::out)
	      : __iostream_type(0), _M_filebuf()
	      {
		this->init(&_M_filebuf);
		this->open(__s, __mode);
	      }
	#endif
	
	      /**
	       *  @brief  The destructor does nothing.
	       *
	       *  The file is closed by the filebuf object, not the formatting
	       *  stream.
	       */
	      ~basic_fstream()
	      { }
	
	      // Members:
	      /**
	       *  @brief  Accessing the underlying buffer.
	       *  @return  The current basic_filebuf buffer.
	       *
	       *  This hides both signatures of std::basic_ios::rdbuf().
	       */
	      __filebuf_type*
	      rdbuf() const
	      { return const_cast<__filebuf_type*>(&_M_filebuf); }
	
	      /**
	       *  @brief  Wrapper to test for an open file.
	       *  @return  @c rdbuf()->is_open()
	       */
	      bool
	      is_open()
	      { return _M_filebuf.is_open(); }
	
	      // _GLIBCXX_RESOLVE_LIB_DEFECTS
	      // 365. Lack of const-qualification in clause 27
	      bool
	      is_open() const
	      { return _M_filebuf.is_open(); }
	
	      /**
	       *  @brief  Opens an external file.
	       *  @param  __s  The name of the file.
	       *  @param  __mode  The open mode flags.
	       *
	       *  Calls @c std::basic_filebuf::open(__s,__mode).  If that
	       *  function fails, @c failbit is set in the stream's error state.
	       *
	       *  Tip:  When using std::string to hold the filename, you must use
	       *  .c_str() before passing it to this constructor.
	       */
	      void
	      open(const char* __s,
		   ios_base::openmode __mode = ios_base::in | ios_base::out)
	      {
		if (!_M_filebuf.open(__s, __mode))
		  this->setstate(ios_base::failbit);
		else
		  // _GLIBCXX_RESOLVE_LIB_DEFECTS
		  // 409. Closing an fstream should clear error state
		  this->clear();
	      }
	
	#if __cplusplus >= 201103L
	      /**
	       *  @brief  Opens an external file.
	       *  @param  __s  The name of the file.
	       *  @param  __mode  The open mode flags.
	       *
	       *  Calls @c std::basic_filebuf::open(__s,__mode).  If that
	       *  function fails, @c failbit is set in the stream's error state.
	       */
	      void
	      open(const std::string& __s,
		   ios_base::openmode __mode = ios_base::in | ios_base::out)
	      {
		if (!_M_filebuf.open(__s, __mode))
		  this->setstate(ios_base::failbit);
		else
		  // _GLIBCXX_RESOLVE_LIB_DEFECTS
		  // 409. Closing an fstream should clear error state
		  this->clear();
	      }
	#endif
	
	      /**
	       *  @brief  Close the file.
	       *
	       *  Calls @c std::basic_filebuf::close().  If that function
	       *  fails, @c failbit is set in the stream's error state.
	       */
	      void
	      close()
	      {
		if (!_M_filebuf.close())
		  this->setstate(ios_base::failbit);
	      }
	    };
	
	_GLIBCXX_END_NAMESPACE_VERSION
	} // namespace
	
	#include <bits/fstream.tcc>
	
	#endif /* _GLIBCXX_FSTREAM */