1/*
2 * Copyright (c) 1999
3 * Silicon Graphics Computer Systems, Inc.
4 *
5 * Copyright (c) 1999
6 * Boris Fomitchev
7 *
8 * This material is provided "as is", with absolutely no warranty expressed
9 * or implied. Any use is at your own risk.
10 *
11 * Permission to use or copy this software for any purpose is hereby granted
12 * without fee, provided the above notices are retained on all copies.
13 * Permission to modify the code and to distribute modified code is granted,
14 * provided the above notices are retained, and a notice that the code was
15 * modified is included with the above copyright notice.
16 *
17 */
18
19// This header defines two streambufs:
20// stdio_istreambuf, a read-only streambuf synchronized with a C stdio
21// FILE object
22// stdio_ostreambuf, a write-only streambuf synchronized with a C stdio
23// FILE object.
24// Note that neither stdio_istreambuf nor stdio_ostreambuf is a template;
25// both classes are derived from basic_streambuf<char, char_traits<char> >.
26
27// Note: the imbue() member function is a no-op.  In particular, these
28// classes assume that codecvt<char, char, mbstate_t> is always an identity
29// transformation.  This is true of the default locale, and of all locales
30// defined for the C I/O library.  If you need to use a locale where
31// the codecvt<char, char, mbstate_t> facet performs a nontrivial
32// conversion, then you should use basic_filebuf<> instead of stdio_istreambuf
33// or stdio_ostreambuf.  (If you don't understand what any of this means,
34// then it's not a feature you need to worry about.  Locales where
35// codecvt<char, char, mbstate_t> does something nontrivial are a rare
36// corner case.)
37
38
39#ifndef _STLP_STDIO_STREAMBUF
40#define _STLP_STDIO_STREAMBUF
41
42#include <streambuf>
43#include <cstdio>              // For FILE.
44
45_STLP_BEGIN_NAMESPACE
46_STLP_MOVE_TO_PRIV_NAMESPACE
47
48// Base class for features common to stdio_istreambuf and stdio_ostreambuf
49class stdio_streambuf_base :
50  public basic_streambuf<char, char_traits<char> > /* FILE_basic_streambuf */ {
51public:                         // Constructor, destructor.
52  // The argument may not be null.  It must be an open file pointer.
53  stdio_streambuf_base(FILE*);
54
55  // The destructor flushes the stream, but does not close it.
56  ~stdio_streambuf_base();
57
58protected:                      // Virtual functions from basic_streambuf.
59  streambuf* setbuf(char*, streamsize);
60
61  pos_type seekoff(off_type, ios_base::seekdir,
62                   ios_base::openmode
63                          = ios_base::in | ios_base::out);
64  pos_type seekpos(pos_type,
65                   ios_base::openmode
66                          = ios_base::in | ios_base::out);
67  int sync();
68
69protected:
70  FILE* _M_file;
71};
72
73class stdio_istreambuf : public stdio_streambuf_base {
74public:                         // Constructor, destructor.
75  stdio_istreambuf(FILE* __f) : stdio_streambuf_base(__f) {}
76  ~stdio_istreambuf();
77
78protected:                      // Virtual functions from basic_streambuf.
79  streamsize showmanyc();
80  int_type underflow();
81  int_type uflow();
82  virtual int_type pbackfail(int_type c = traits_type::eof());
83};
84
85class stdio_ostreambuf : public stdio_streambuf_base {
86public:                         // Constructor, destructor.
87  stdio_ostreambuf(FILE* __f) : stdio_streambuf_base(__f) {}
88  ~stdio_ostreambuf();
89
90protected:                      // Virtual functions from basic_streambuf.
91  streamsize showmanyc();
92  int_type overflow(int_type c = traits_type::eof());
93};
94
95_STLP_MOVE_TO_STD_NAMESPACE
96_STLP_END_NAMESPACE
97
98#endif /* _STLP_STDIO_STREAMBUF */
99
100// Local Variables:
101// mode:C++
102// End:
103