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──The Microsoft iostream Classes────────────────────────────────────────────
 
  fstream();
  fstream( const char* szName, int nMode,
           int nProt = filebuf::openprot );
  fstream( filedesc fd );
  fstream( filedesc fd, char* pch, int nLength );
 
  Parameter   Description
 
  <szName>    The name of the file to be opened during construction.
 
  <nMode>     An integer that contains mode bits defined as ios
              enumerators that can be combined with the bitwise-OR (|)
              operator:
 
              Value            Meaning
 
              ios::app         The function performs a seek to the end of
                               file. When new bytes are written to the
                               file, they are always appended to the end,
                               even if the position is moved with the
                               ostream::seekp function.
 
              ios::ate         The function performs a seek to the end of
                               file. When the first new byte is written to
                               the file, it is appended to the end, but
                               when subsequent bytes are written, they are
                               written to the current position.
 
              ios::in          The file is opened for input. The original
                               file (if it exists), will not be
                               truncated.
 
              ios::out         The file is opened for output.
 
              ios::trunc       If the file already exists, its contents
                               are discarded. This mode is implied if
                               ios::out is specified and ios::ate,
                               ios::app, and ios:in are not specified.
 
              ios::nocreate    If the file does not already exist, the
                               function fails.
 
              ios::noreplace   If the file already exists, the function
                               fails.
 
              ios::binary      Opens the file in binary mode (the default
                               is text mode).
 
              Note that there is no ios::in or ios::out default mode for
              fstream objects. You must specify both modes if your fstream
              object must both read and write files.
 
  <nProt>     The file protection specification; defaults to the static
              integer filebuf::openprot that is equivalent to
              filebuf::sh_compat. The possible <nProt> values are as
              follows:
 
              Value                Meaning
 
              filebuf::sh_compat   Compatibility share mode.
 
              filebuf::sh_none     Exclusive mode──no sharing.
 
              filebuf::sh_read     Read sharing allowed.
 
              filebuf::sh_write    Write sharing allowed.
 
              The filebuf::sh_read and filebuf::sh_write modes can be
              combined with the logical OR (|) operator.
 
  <fd>        A file descriptor as returned by a call to the run-time
              function _open or _sopen. filedesc is a typedef equivalent
              to int.
 
  <pch>       Pointer to a previously allocated reserve area of length
              <nLength>. A NULL value (or <nLength> = 0) indicates that
              the stream will be unbuffered.
 
  <nLength>   The length (in bytes) of the reserve area (0 = unbuffered).
 
  Remarks
 
  The four fstream constructors are described as follows:
  Constructor                        Description
 
  fstream()                          Constructs an fstream object without
                                     opening a file.
 
  fstream( const char*, int, int )   Contructs an fstream object, opening
                                     the specified file.
 
  fstream( filedesc )                Constructs an fstream object that is
                                     attached to an open file.
 
  fstream( filedesc, char*, int )    Constructs an fstream object that is
                                     associated with a filebuf object. The
                                     filebuf object is attached to an open
                                     file and to a specified reserve
                                     area.
 
  All fstream constructors construct a filebuf object. The first three use
  an internally allocated reserve area, but the fourth uses a
  user-allocated area. The user-allocated area is not automatically
  released during destruction.
 
 
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