/*

 * Copyright (c) 1999

 * Silicon Graphics Computer Systems, Inc.

 *

 * Copyright (c) 1999 

 * Boris Fomitchev

 *

 * This material is provided "as is", with absolutely no warranty expressed

 * or implied. Any use is at your own risk.

 *

 * Permission to use or copy this software for any purpose is hereby granted 

 * without fee, provided the above notices are retained on all copies.

 * Permission to modify the code and to distribute modified code is granted,

 * provided the above notices are retained, and a notice that the code was

 * modified is included with the above copyright notice.

 *

 */ 

// This header is an extension.  It defines two streambufs:

// stdio_istreambuf, a read-only streambuf synchronized with a C stdio

// FILE object, and stdio_ostreambuf, a write-only streambuf

// synchronized with a C stdio FILE object.  Note that neither 

// stdio_istreambuf nor stdio_ostreambuf is a template; both classes

// are derived from basic_streambuf<char, char_traits<char> >.

// Note: the imbue() member function is a no-op.  In particular, these

// classes assume that codecvt<char, char, mbstate_t> is always an identity

// transformation.  This is true of the default locale, and of all locales

// defined for the C I/O library.  If you need to use a locale where 

// the codecvt<char, char, mbstate_t> facet performs a nontrivial 

// conversion, then you should use basic_filebuf<> instead of stdio_istreambuf

// or stdio_ostreambuf.  (If you don't understand what any of this means, 

// then it's not a feature you need to worry about.  Locales where 

// codecvt<char, char, mbstate_t> does something nontrivial are a rare

// corner case.)

#ifndef _STLP_STDIO_STREAMBUF

#define _STLP_STDIO_STREAMBUF

#if !defined(STLP_WINCE)

#include <streambuf>            // For basic_streambuf<>

#include <cstdio>              // For FILE.

# ifndef _STLP_HAS_NO_NAMESPACES

// This is an extension.  It is in namespace SGI, not namespace std

namespace _SgI {

# ifdef _STLP_USE_NAMESPACES

using namespace _STLP_STD;

  // MSVC needs this

using _STLP_STD::streamsize;

using _STLP_STD::streambuf;

using _STLP_STD::basic_streambuf;

using _STLP_STD::ios_base;

  // using _STLP_STD::ios_base::openmode;

# endif

# endif

// Base class for features common to stdio_istreambuf and stdio_ostreambuf

class stdio_streambuf_base : public basic_streambuf<char, _STLP_STD::char_traits<char> >

{

public:                         // Constructor, destructor.

  // The argument may not be null.  It must be an open file pointer.

  stdio_streambuf_base(FILE*);

  // The destructor flushes the stream, but does not close it.

  ~stdio_streambuf_base();

protected:                      // Virtual functions from basic_streambuf.

  streambuf* setbuf(char*, streamsize);

  pos_type seekoff(off_type, ios_base::seekdir,

                   ios_base::openmode

                          = ios_base::in | ios_base::out);

  pos_type seekpos(pos_type,

                   ios_base::openmode

                          = ios_base::in | ios_base::out);

  int sync();

protected:

  FILE* _M_file;

};

class stdio_istreambuf : public stdio_streambuf_base

{

public:                         // Constructor, destructor.

  stdio_istreambuf(FILE* __f) : stdio_streambuf_base(__f) {}

  ~stdio_istreambuf();

protected:                      // Virtual functions from basic_streambuf.

  streamsize showmanyc();

  int_type underflow();

  int_type uflow();

  virtual int_type pbackfail(int_type c = traits_type::eof());

};

class stdio_ostreambuf : public stdio_streambuf_base

{

public:                         // Constructor, destructor.

  stdio_ostreambuf(FILE* __f) : stdio_streambuf_base(__f) {}

  ~stdio_ostreambuf();

protected:                      // Virtual functions from basic_streambuf.

  streamsize showmanyc();

  int_type overflow(int_type c = traits_type::eof());

};

# ifndef _STLP_HAS_NO_NAMESPACES

} // Close namespace _SgI.

# endif

#endif /* _STLP_STDIO_STREAMBUF */

#endif /* _STLP_WINCE */

// Local Variables:

// mode:C++

// End: