libstdc++
streambuf.tcc
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1 // Stream buffer classes -*- C++ -*-
2 
3 // Copyright (C) 1997-2021 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file bits/streambuf.tcc
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{streambuf}
28  */
29 
30 //
31 // ISO C++ 14882: 27.5 Stream buffers
32 //
33 
34 #ifndef _STREAMBUF_TCC
35 #define _STREAMBUF_TCC 1
36 
37 #pragma GCC system_header
38 
39 namespace std _GLIBCXX_VISIBILITY(default)
40 {
41 _GLIBCXX_BEGIN_NAMESPACE_VERSION
42 
43  template<typename _CharT, typename _Traits>
46  xsgetn(char_type* __s, streamsize __n)
47  {
48  streamsize __ret = 0;
49  while (__ret < __n)
50  {
51  const streamsize __buf_len = this->egptr() - this->gptr();
52  if (__buf_len)
53  {
54  const streamsize __remaining = __n - __ret;
55  const streamsize __len = std::min(__buf_len, __remaining);
56  traits_type::copy(__s, this->gptr(), __len);
57  __ret += __len;
58  __s += __len;
59  this->__safe_gbump(__len);
60  }
61 
62  if (__ret < __n)
63  {
64  const int_type __c = this->uflow();
65  if (!traits_type::eq_int_type(__c, traits_type::eof()))
66  {
67  traits_type::assign(*__s++, traits_type::to_char_type(__c));
68  ++__ret;
69  }
70  else
71  break;
72  }
73  }
74  return __ret;
75  }
76 
77  template<typename _CharT, typename _Traits>
80  xsputn(const char_type* __s, streamsize __n)
81  {
82  streamsize __ret = 0;
83  while (__ret < __n)
84  {
85  const streamsize __buf_len = this->epptr() - this->pptr();
86  if (__buf_len)
87  {
88  const streamsize __remaining = __n - __ret;
89  const streamsize __len = std::min(__buf_len, __remaining);
90  traits_type::copy(this->pptr(), __s, __len);
91  __ret += __len;
92  __s += __len;
93  this->__safe_pbump(__len);
94  }
95 
96  if (__ret < __n)
97  {
98  int_type __c = this->overflow(traits_type::to_int_type(*__s));
99  if (!traits_type::eq_int_type(__c, traits_type::eof()))
100  {
101  ++__ret;
102  ++__s;
103  }
104  else
105  break;
106  }
107  }
108  return __ret;
109  }
110 
111  // Conceivably, this could be used to implement buffer-to-buffer
112  // copies, if this was ever desired in an un-ambiguous way by the
113  // standard.
114  template<typename _CharT, typename _Traits>
115  streamsize
116  __copy_streambufs_eof(basic_streambuf<_CharT, _Traits>* __sbin,
118  bool& __ineof)
119  {
120  streamsize __ret = 0;
121  __ineof = true;
122  typename _Traits::int_type __c = __sbin->sgetc();
123  while (!_Traits::eq_int_type(__c, _Traits::eof()))
124  {
125  __c = __sbout->sputc(_Traits::to_char_type(__c));
126  if (_Traits::eq_int_type(__c, _Traits::eof()))
127  {
128  __ineof = false;
129  break;
130  }
131  ++__ret;
132  __c = __sbin->snextc();
133  }
134  return __ret;
135  }
136 
137  template<typename _CharT, typename _Traits>
138  inline streamsize
139  __copy_streambufs(basic_streambuf<_CharT, _Traits>* __sbin,
140  basic_streambuf<_CharT, _Traits>* __sbout)
141  {
142  bool __ineof;
143  return __copy_streambufs_eof(__sbin, __sbout, __ineof);
144  }
145 
146  // Inhibit implicit instantiations for required instantiations,
147  // which are defined via explicit instantiations elsewhere.
148 #if _GLIBCXX_EXTERN_TEMPLATE
149  extern template class basic_streambuf<char>;
150 
151  extern template
152  streamsize
153  __copy_streambufs(basic_streambuf<char>*,
154  basic_streambuf<char>*);
155 
156 #ifdef _GLIBCXX_USE_WCHAR_T
157  extern template class basic_streambuf<wchar_t>;
158 
159  extern template
160  streamsize
161  __copy_streambufs(basic_streambuf<wchar_t>*,
162  basic_streambuf<wchar_t>*);
163 #endif
164 #endif
165 
166 _GLIBCXX_END_NAMESPACE_VERSION
167 } // namespace std
168 
169 #endif
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:230
ISO C++ entities toplevel namespace is std.
ptrdiff_t streamsize
Integral type for I/O operation counts and buffer sizes.
Definition: postypes.h:68
The actual work of input and output (interface).
Definition: streambuf:123
traits_type::int_type int_type
Definition: streambuf:133
virtual streamsize xsputn(const char_type *__s, streamsize __n)
Multiple character insertion.
Definition: streambuf.tcc:80
virtual streamsize xsgetn(char_type *__s, streamsize __n)
Multiple character extraction.
Definition: streambuf.tcc:46
int_type snextc()
Getting the next character.
Definition: streambuf:303
int_type sgetc()
Getting the next character.
Definition: streambuf:343
int_type sputc(char_type __c)
Entry point for all single-character output functions.
Definition: streambuf:429