| /* This is part of libio/iostream, providing -*- C++ -*- input/output. |
| Copyright (C) 1993 Free Software Foundation |
| |
| This file is part of the GNU IO 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 2, 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. |
| |
| You should have received a copy of the GNU General Public License |
| along with this library; see the file COPYING. If not, write to the Free |
| Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| |
| As a special exception, if you link this library with files |
| compiled with a GNU compiler to produce an executable, this does not cause |
| the resulting executable to be covered by the GNU General Public License. |
| This exception does not however invalidate any other reasons why |
| the executable file might be covered by the GNU General Public License. |
| |
| Written by Per Bothner (bothner@cygnus.com). */ |
| |
| #ifndef _INDSTREAM_H |
| #define _INDSTREAM_H |
| |
| #ifdef __GNUG__ |
| #pragma interface |
| #endif |
| |
| #include <iostream.h> |
| |
| extern "C++" { |
| // An indirectbuf is one that forwards all of its I/O requests |
| // to another streambuf. |
| // All get-related requests are sent to get_stream(). |
| // All put-related requests are sent to put_stream(). |
| |
| // An indirectbuf can be used to implement Common Lisp |
| // synonym-streams and two-way-streams. |
| // |
| // class synonymbuf : public indirectbuf { |
| // Symbol *sym; |
| // synonymbuf(Symbol *s) { sym = s; } |
| // virtual streambuf *lookup_stream(int mode) { |
| // return coerce_to_streambuf(lookup_value(sym)); } |
| // }; |
| |
| class indirectbuf : public streambuf { |
| protected: |
| streambuf *_get_stream; // Optional cache for get_stream(). |
| streambuf *_put_stream; // Optional cache for put_stream(). |
| int _delete_flags; |
| public: |
| streambuf *get_stream() |
| { return _get_stream ? _get_stream : lookup_stream(ios::in); } |
| streambuf *put_stream() |
| { return _put_stream ? _put_stream : lookup_stream(ios::out); } |
| virtual streambuf *lookup_stream(int/*mode*/) { return NULL; } // ERROR! |
| indirectbuf(streambuf *get=NULL, streambuf *put=NULL, int delete_mode=0); |
| virtual ~indirectbuf(); |
| virtual streamsize xsputn(const char* s, streamsize n); |
| virtual streamsize xsgetn(char* s, streamsize n); |
| virtual int underflow(); |
| virtual int uflow(); |
| virtual int overflow(int c = EOF); |
| virtual streampos seekoff(streamoff, _seek_dir, int mode=ios::in|ios::out); |
| virtual streampos seekpos(streampos pos, int mode = ios::in|ios::out); |
| virtual int sync(); |
| virtual int pbackfail(int c); |
| }; |
| } // extern "C++" |
| |
| #endif /* !_INDSTREAM_H */ |