ostream

symbian上STL模板库的实现

       *  Tries to insert @a c.
       *
       *  @note  This function is not overloaded on signed char and
       *         unsigned char.
      */
      __ostream_type& 
      put(char_type __c);

      // Core write functionality, without sentry.
      void
      _M_write(const char_type* __s, streamsize __n)
      {
	streamsize __put = this->rdbuf()->sputn(__s, __n);
	if (__put != __n)
	  this->setstate(ios_base::badbit);
      }

      /**
       *  @brief  Character string insertion.
       *  @param  s  The array to insert.
       *  @param  n  Maximum number of characters to insert.
       *  @return  *this
       *
       *  Characters are copied from @a s and inserted into the stream until
       *  one of the following happens:
       *
       *  - @a n characters are inserted
       *  - inserting into the output sequence fails (in this case, badbit
       *    will be set in the stream's error state)
       *
       *  @note  This function is not overloaded on signed char and
       *         unsigned char.
      */
      __ostream_type& 
      write(const char_type* __s, streamsize __n);
      //@}

      /**
       *  @brief  Synchronizing the stream buffer.
       *  @return  *this
       *
       *  If @c rdbuf() is a null pointer, changes nothing.
       *
       *  Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1,
       *  sets badbit.
      */
      __ostream_type& 
      flush();

      // [27.6.2.4] seek members
      /**
       *  @brief  Getting the current write position.
       *  @return  A file position object.
       *
       *  If @c fail() is not false, returns @c pos_type(-1) to indicate
       *  failure.  Otherwise returns @c rdbuf()->pubseekoff(0,cur,out).
      */
      pos_type 
      tellp();

      /**
       *  @brief  Changing the current write position.
       *  @param  pos  A file position object.
       *  @return  *this
       *
       *  If @c fail() is not true, calls @c rdbuf()->pubseekpos(pos).  If
       *  that function fails, sets failbit.
      */
      __ostream_type& 
      seekp(pos_type);

      /**
       *  @brief  Changing the current write position.
       *  @param  off  A file offset object.
       *  @param  dir  The direction in which to seek.
       *  @return  *this
       *
       *  If @c fail() is not true, calls @c rdbuf()->pubseekoff(off,dir).
       *  If that function fails, sets failbit.
      */
       __ostream_type& 
      seekp(off_type, ios_base::seekdir);
      
    protected:
      explicit 
      basic_ostream() { }
    };

  /**
   *  @brief  Performs setup work for output streams.
   *
   *  Objects of this class are created before all of the standard
   *  inserters are run.  It is responsible for "exception-safe prefix and
   *  suffix operations."  Additional actions may be added by the
   *  implementation, and we list them in
   *  http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/howto.html#5
   *  under [27.6] notes.
  */
  template <typename _CharT, typename _Traits>
    class basic_ostream<_CharT, _Traits>::sentry
    {
      // Data Members:
      bool 				_M_ok;
      basic_ostream<_CharT,_Traits>& 	_M_os;
      
    public:
      /**
       *  @brief  The constructor performs preparatory work.
       *  @param  os  The output stream to guard.
       *
       *  If the stream state is good (@a os.good() is true), then if the
       *  stream is tied to another output stream, @c is.tie()->flush()
       *  is called to synchronize the output sequences.
       *
       *  If the stream state is still good, then the sentry state becomes
       *  true ("okay").
      */
      explicit
      sentry(basic_ostream<_CharT,_Traits>& __os);

      /**
       *  @brief  Possibly flushes the stream.
       *
       *  If @c ios_base::unitbuf is set in @c os.flags(), and
       *  @c std::uncaught_exception() is true, the sentry destructor calls
       *  @c flush() on the output stream.
      */
      ~sentry()
      {
	// XXX MT
	if (_M_os.flags() & ios_base::unitbuf && !uncaught_exception())
	  {
	    // Can't call flush directly or else will get into recursive lock.
	    if (_M_os.rdbuf() && _M_os.rdbuf()->pubsync() == -1)
	      _M_os.setstate(ios_base::badbit);
	  }
      }

      /**
       *  @brief  Quick status checking.
       *  @return  The sentry state.
       *
       *  For ease of use, sentries may be converted to booleans.  The
       *  return value is that of the sentry state (true == okay).
      */
      operator bool() const
      { return _M_ok; }
    };

  // [27.6.2.5.4] character insertion templates
  //@{
  /**
   *  @brief  Character inserters
   *  @param  out  An output stream.
   *  @param  c  A character.
   *  @return  out
   *
   *  Behaves like one of the formatted arithmetic inserters described in
   *  std::basic_ostream.  After constructing a sentry object with good
   *  status, this function inserts a single character and any required
   *  padding (as determined by [22.2.2.2.2]).  @c out.width(0) is then
   *  called.
   *
   *  If @a c is of type @c char and the character type of the stream is not
   *  @c char, the character is widened before insertion.
  */
  template<typename _CharT, typename _Traits>
    basic_ostream<_CharT, _Traits>&
    operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c);

  template<typename _CharT, typename _Traits>
    basic_ostream<_CharT, _Traits>&
    operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
    { return (__out << __out.widen(__c)); }

  // Specialization
  template <class _Traits> 
    basic_ostream<char, _Traits>&
    operator<<(basic_ostream<char, _Traits>& __out, char __c);

  // Signed and unsigned
  template<class _Traits>
    basic_ostream<char, _Traits>&
    operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
    { return (__out << static_cast<char>(__c)); }
  
  template<class _Traits>
    basic_ostream<char, _Traits>&
    operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
    { return (__out << static_cast<char>(__c)); }
  //@}
  
  //@{
  /**
   *  @brief  String inserters
   *  @param  out  An output stream.
   *  @param  s  A character string.
   *  @return  out
   *  @pre  @a s must be a non-NULL pointer
   *
   *  Behaves like one of the formatted arithmetic inserters described in
   *  std::basic_ostream.  After constructing a sentry object with good
   *  status, this function inserts @c traits::length(s) characters starting
   *  at @a s, widened if necessary, followed by any required padding (as
   *  determined by [22.2.2.2.2]).  @c out.width(0) is then called.
  */
  template<typename _CharT, typename _Traits>
    basic_ostream<_CharT, _Traits>&
    operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s);

  template<typename _CharT, typename _Traits>
    basic_ostream<_CharT, _Traits> &
    operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s);

  // Partial specializationss
  template<class _Traits>
    basic_ostream<char, _Traits>&
    operator<<(basic_ostream<char, _Traits>& __out, const char* __s);
 
  // Signed and unsigned
  template<class _Traits>
    basic_ostream<char, _Traits>&
    operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
    { return (__out << reinterpret_cast<const char*>(__s)); }

  template<class _Traits>
    basic_ostream<char, _Traits> &
    operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
    { return (__out << reinterpret_cast<const char*>(__s)); }
  //@}

  // [27.6.2.7] standard basic_ostream manipulators
  /**
   *  @brief  Write a newline and flush the stream.
   *
   *  This manipulator is often mistakenly used when a simple newline is
   *  desired, leading to poor buffering performance.  See
   *  http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#2 for more
   *  on this subject.
  */
  template<typename _CharT, typename _Traits>
    basic_ostream<_CharT, _Traits>& 
    endl(basic_ostream<_CharT, _Traits>& __os)
    { return flush(__os.put(__os.widen('\n'))); }

  /**
   *  @brief  Write a null character into the output sequence.
   *
   *  "Null character" is @c CharT() by definition.  For CharT of @c char,
   *  this correctly writes the ASCII @c NUL character string terminator.
  */
  template<typename _CharT, typename _Traits>
    basic_ostream<_CharT, _Traits>& 
    ends(basic_ostream<_CharT, _Traits>& __os)
    { return __os.put(_CharT()); }
  
  /**
   *  @brief  Flushes the output stream.
   *
   *  This manipulator simply calls the stream's @c flush() member function.
  */
  template<typename _CharT, typename _Traits>
    basic_ostream<_CharT, _Traits>& 
    flush(basic_ostream<_CharT, _Traits>& __os)
    { return __os.flush(); }

} // namespace std

#ifndef _GLIBCXX_EXPORT_TEMPLATE
# include <bits/ostream.tcc>
#endif

#endif	/* _GLIBCXX_OSTREAM */