libstdc++
basic_ios.tcc
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1 // basic_ios member functions -*- C++ -*-
2 
3 // Copyright (C) 1999-2021 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/basic_ios.tcc
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{ios}
28  */
29 
30 #ifndef _BASIC_IOS_TCC
31 #define _BASIC_IOS_TCC 1
32 
33 #pragma GCC system_header
34 
35 namespace std _GLIBCXX_VISIBILITY(default)
36 {
37 _GLIBCXX_BEGIN_NAMESPACE_VERSION
38 
39  template<typename _CharT, typename _Traits>
40  void
42  {
43  if (this->rdbuf())
44  _M_streambuf_state = __state;
45  else
46  _M_streambuf_state = __state | badbit;
47  if (this->exceptions() & this->rdstate())
48  __throw_ios_failure(__N("basic_ios::clear"));
49  }
50 
51  template<typename _CharT, typename _Traits>
54  {
55  basic_streambuf<_CharT, _Traits>* __old = _M_streambuf;
56  _M_streambuf = __sb;
57  this->clear();
58  return __old;
59  }
60 
61  template<typename _CharT, typename _Traits>
64  {
65  // _GLIBCXX_RESOLVE_LIB_DEFECTS
66  // 292. effects of a.copyfmt (a)
67  if (this != std::__addressof(__rhs))
68  {
69  // Per 27.1.1, do not call imbue, yet must trash all caches
70  // associated with imbue()
71 
72  // Alloc any new word array first, so if it fails we have "rollback".
73  _Words* __words = (__rhs._M_word_size <= _S_local_word_size) ?
74  _M_local_word : new _Words[__rhs._M_word_size];
75 
76  // Bump refs before doing callbacks, for safety.
77  _Callback_list* __cb = __rhs._M_callbacks;
78  if (__cb)
79  __cb->_M_add_reference();
80  _M_call_callbacks(erase_event);
81  if (_M_word != _M_local_word)
82  {
83  delete [] _M_word;
84  _M_word = 0;
85  }
86  _M_dispose_callbacks();
87 
88  // NB: Don't want any added during above.
89  _M_callbacks = __cb;
90  for (int __i = 0; __i < __rhs._M_word_size; ++__i)
91  __words[__i] = __rhs._M_word[__i];
92  _M_word = __words;
93  _M_word_size = __rhs._M_word_size;
94 
95  this->flags(__rhs.flags());
96  this->width(__rhs.width());
97  this->precision(__rhs.precision());
98  this->tie(__rhs.tie());
99  this->fill(__rhs.fill());
100  _M_ios_locale = __rhs.getloc();
101  _M_cache_locale(_M_ios_locale);
102 
103  _M_call_callbacks(copyfmt_event);
104 
105  // The next is required to be the last assignment.
106  this->exceptions(__rhs.exceptions());
107  }
108  return *this;
109  }
110 
111  // Locales:
112  template<typename _CharT, typename _Traits>
113  locale
115  {
116  locale __old(this->getloc());
117  ios_base::imbue(__loc);
118  _M_cache_locale(__loc);
119  if (this->rdbuf() != 0)
120  this->rdbuf()->pubimbue(__loc);
121  return __old;
122  }
123 
124  template<typename _CharT, typename _Traits>
125  void
127  {
128  // NB: This may be called more than once on the same object.
129  ios_base::_M_init();
130 
131  // Cache locale data and specific facets used by iostreams.
132  _M_cache_locale(_M_ios_locale);
133 
134  // NB: The 27.4.4.1 Postconditions Table specifies requirements
135  // after basic_ios::init() has been called. As part of this,
136  // fill() must return widen(' ') any time after init() has been
137  // called, which needs an imbued ctype facet of char_type to
138  // return without throwing an exception. Unfortunately,
139  // ctype<char_type> is not necessarily a required facet, so
140  // streams with char_type != [char, wchar_t] will not have it by
141  // default. Because of this, the correct value for _M_fill is
142  // constructed on the first call of fill(). That way,
143  // unformatted input and output with non-required basic_ios
144  // instantiations is possible even without imbuing the expected
145  // ctype<char_type> facet.
146  _M_fill = _CharT();
147  _M_fill_init = false;
148 
149  _M_tie = 0;
150  _M_exception = goodbit;
151  _M_streambuf = __sb;
152  _M_streambuf_state = __sb ? goodbit : badbit;
153  }
154 
155  template<typename _CharT, typename _Traits>
156  void
158  {
159  if (__builtin_expect(has_facet<__ctype_type>(__loc), true))
160  _M_ctype = std::__addressof(use_facet<__ctype_type>(__loc));
161  else
162  _M_ctype = 0;
163 
164  if (__builtin_expect(has_facet<__num_put_type>(__loc), true))
165  _M_num_put = std::__addressof(use_facet<__num_put_type>(__loc));
166  else
167  _M_num_put = 0;
168 
169  if (__builtin_expect(has_facet<__num_get_type>(__loc), true))
170  _M_num_get = std::__addressof(use_facet<__num_get_type>(__loc));
171  else
172  _M_num_get = 0;
173  }
174 
175  // Inhibit implicit instantiations for required instantiations,
176  // which are defined via explicit instantiations elsewhere.
177 #if _GLIBCXX_EXTERN_TEMPLATE
178  extern template class basic_ios<char>;
179 
180 #ifdef _GLIBCXX_USE_WCHAR_T
181  extern template class basic_ios<wchar_t>;
182 #endif
183 #endif
184 
185 _GLIBCXX_END_NAMESPACE_VERSION
186 } // namespace std
187 
188 #endif
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
Definition: move.h:49
constexpr tuple< _Elements &... > tie(_Elements &... __args) noexcept
tie
Definition: tuple:1698
ISO C++ entities toplevel namespace is std.
Template class basic_ios, virtual base class for all stream classes.
Definition: basic_ios.h:68
void clear(iostate __state=goodbit)
[Re]sets the error state.
Definition: basic_ios.tcc:41
locale imbue(const locale &__loc)
Moves to a new locale.
Definition: basic_ios.tcc:114
basic_ostream< _CharT, _Traits > * tie() const
Fetches the current tied stream.
Definition: basic_ios.h:295
basic_streambuf< _CharT, _Traits > * rdbuf() const
Accessing the underlying buffer.
Definition: basic_ios.h:321
iostate exceptions() const
Throwing exceptions on errors.
Definition: basic_ios.h:222
basic_ios & copyfmt(const basic_ios &__rhs)
Copies fields of __rhs into this.
Definition: basic_ios.tcc:63
void init(basic_streambuf< _CharT, _Traits > *__sb)
All setup is performed here.
Definition: basic_ios.tcc:126
char_type fill() const
Retrieves the empty character.
Definition: basic_ios.h:370
The actual work of input and output (interface).
Definition: streambuf:123
streamsize precision() const
Flags access.
Definition: ios_base.h:719
locale imbue(const locale &__loc)
Setting a new locale.
fmtflags flags() const
Access to format flags.
Definition: ios_base.h:649
streamsize width() const
Flags access.
Definition: ios_base.h:742
locale getloc() const
Locale access.
Definition: ios_base.h:793
Container class for localization functionality.