libstdc++
locale_classes.tcc
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1 // Locale support -*- C++ -*-
2 
3 // Copyright (C) 2007-2024 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/locale_classes.tcc
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{locale}
28  */
29 
30 //
31 // ISO C++ 14882: 22.1 Locales
32 //
33 
34 #ifndef _LOCALE_CLASSES_TCC
35 #define _LOCALE_CLASSES_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 _Facet>
44  locale::
45  locale(const locale& __other, _Facet* __f)
46  {
47  _M_impl = new _Impl(*__other._M_impl, 1);
48 
49  __try
50  { _M_impl->_M_install_facet(&_Facet::id, __f); }
51  __catch(...)
52  {
53  _M_impl->_M_remove_reference();
54  __throw_exception_again;
55  }
56  delete [] _M_impl->_M_names[0];
57  _M_impl->_M_names[0] = 0; // Unnamed.
58  }
59 
60  template<typename _Facet>
61  locale
62  locale::
63  combine(const locale& __other) const
64  {
65  _Impl* __tmp = new _Impl(*_M_impl, 1);
66  __try
67  {
68  __tmp->_M_replace_facet(__other._M_impl, &_Facet::id);
69  }
70  __catch(...)
71  {
72  __tmp->_M_remove_reference();
73  __throw_exception_again;
74  }
75  return locale(__tmp);
76  }
77 
78  template<typename _CharT, typename _Traits, typename _Alloc>
79  bool
80  locale::
82  const basic_string<_CharT, _Traits, _Alloc>& __s2) const
83  {
84  typedef std::collate<_CharT> __collate_type;
85  const __collate_type& __collate = use_facet<__collate_type>(*this);
86  return (__collate.compare(__s1.data(), __s1.data() + __s1.length(),
87  __s2.data(), __s2.data() + __s2.length()) < 0);
88  }
89 
90 #pragma GCC diagnostic push
91 #pragma GCC diagnostic ignored "-Wc++17-extensions"
92  template<typename _Facet>
93  inline const _Facet*
94  __try_use_facet(const locale& __loc) _GLIBCXX_NOTHROW
95  {
96  const size_t __i = _Facet::id._M_id();
97  const locale::facet** __facets = __loc._M_impl->_M_facets;
98 
99  // We know these standard facets are always installed in every locale
100  // so dynamic_cast always succeeds, just use static_cast instead.
101 #define _GLIBCXX_STD_FACET(...) \
102  if _GLIBCXX_CONSTEXPR (__is_same(_Facet, __VA_ARGS__)) \
103  return static_cast<const _Facet*>(__facets[__i])
104 
105  _GLIBCXX_STD_FACET(ctype<char>);
106  _GLIBCXX_STD_FACET(num_get<char>);
107  _GLIBCXX_STD_FACET(num_put<char>);
108  _GLIBCXX_STD_FACET(codecvt<char, char, mbstate_t>);
109  _GLIBCXX_STD_FACET(collate<char>);
110  _GLIBCXX_STD_FACET(moneypunct<char>);
111  _GLIBCXX_STD_FACET(moneypunct<char, true>);
112  _GLIBCXX_STD_FACET(money_get<char>);
113  _GLIBCXX_STD_FACET(money_put<char>);
114  _GLIBCXX_STD_FACET(numpunct<char>);
115  _GLIBCXX_STD_FACET(time_get<char>);
116  _GLIBCXX_STD_FACET(time_put<char>);
117  _GLIBCXX_STD_FACET(messages<char>);
118 
119 #ifdef _GLIBCXX_USE_WCHAR_T
120  _GLIBCXX_STD_FACET(ctype<wchar_t>);
121  _GLIBCXX_STD_FACET(num_get<wchar_t>);
122  _GLIBCXX_STD_FACET(num_put<wchar_t>);
123  _GLIBCXX_STD_FACET(codecvt<wchar_t, char, mbstate_t>);
124  _GLIBCXX_STD_FACET(collate<wchar_t>);
125  _GLIBCXX_STD_FACET(moneypunct<wchar_t>);
126  _GLIBCXX_STD_FACET(moneypunct<wchar_t, true>);
127  _GLIBCXX_STD_FACET(money_get<wchar_t>);
128  _GLIBCXX_STD_FACET(money_put<wchar_t>);
129  _GLIBCXX_STD_FACET(numpunct<wchar_t>);
130  _GLIBCXX_STD_FACET(time_get<wchar_t>);
131  _GLIBCXX_STD_FACET(time_put<wchar_t>);
132  _GLIBCXX_STD_FACET(messages<wchar_t>);
133 #endif
134 #if __cplusplus >= 201103L
135  _GLIBCXX_STD_FACET(codecvt<char16_t, char, mbstate_t>);
136  _GLIBCXX_STD_FACET(codecvt<char32_t, char, mbstate_t>);
137 #endif
138 
139 #undef _GLIBCXX_STD_FACET
140 
141  if (__i >= __loc._M_impl->_M_facets_size || !__facets[__i])
142  return 0;
143 
144 #if __cpp_rtti
145  return dynamic_cast<const _Facet*>(__facets[__i]);
146 #else
147  return static_cast<const _Facet*>(__facets[__i]);
148 #endif
149  }
150 #pragma GCC diagnostic pop
151 
152  /**
153  * @brief Test for the presence of a facet.
154  * @ingroup locales
155  *
156  * has_facet tests the locale argument for the presence of the facet type
157  * provided as the template parameter. Facets derived from the facet
158  * parameter will also return true.
159  *
160  * @tparam _Facet The facet type to test the presence of.
161  * @param __loc The locale to test.
162  * @return true if @p __loc contains a facet of type _Facet, else false.
163  */
164  template<typename _Facet>
165  _GLIBCXX_NODISCARD
166  inline bool
167  has_facet(const locale& __loc) throw()
168  {
169 #if __cplusplus >= 201103L
170  static_assert(__is_base_of(locale::facet, _Facet),
171  "template argument must be derived from locale::facet");
172 #else
173  (void) static_cast<const _Facet*>(static_cast<const locale::facet*>(0));
174 #endif
175  return std::__try_use_facet<_Facet>(__loc) != 0;
176  }
177 
178  /**
179  * @brief Return a facet.
180  * @ingroup locales
181  *
182  * use_facet looks for and returns a reference to a facet of type Facet
183  * where Facet is the template parameter. If has_facet(locale) is true,
184  * there is a suitable facet to return. It throws std::bad_cast if the
185  * locale doesn't contain a facet of type Facet.
186  *
187  * @tparam _Facet The facet type to access.
188  * @param __loc The locale to use.
189  * @return Reference to facet of type Facet.
190  * @throw std::bad_cast if @p __loc doesn't contain a facet of type _Facet.
191  */
192 #pragma GCC diagnostic push
193 #pragma GCC diagnostic ignored "-Wdangling-reference"
194  template<typename _Facet>
195  _GLIBCXX_NODISCARD
196  inline const _Facet&
197  use_facet(const locale& __loc)
198  {
199 #if __cplusplus >= 201103L
200  static_assert(__is_base_of(locale::facet, _Facet),
201  "template argument must be derived from locale::facet");
202 #else
203  (void) static_cast<const _Facet*>(static_cast<const locale::facet*>(0));
204 #endif
205  if (const _Facet* __f = std::__try_use_facet<_Facet>(__loc))
206  return *__f;
207  __throw_bad_cast();
208  }
209 #pragma GCC diagnostic pop
210 
211 
212  // Generic version does nothing.
213  template<typename _CharT>
214  int
215  collate<_CharT>::_M_compare(const _CharT*, const _CharT*) const throw ()
216  { return 0; }
217 
218  // Generic version does nothing.
219  template<typename _CharT>
220  size_t
221  collate<_CharT>::_M_transform(_CharT*, const _CharT*, size_t) const throw ()
222  { return 0; }
223 
224  template<typename _CharT>
225  int
227  do_compare(const _CharT* __lo1, const _CharT* __hi1,
228  const _CharT* __lo2, const _CharT* __hi2) const
229  {
230  // strcoll assumes zero-terminated strings so we make a copy
231  // and then put a zero at the end.
232  const string_type __one(__lo1, __hi1);
233  const string_type __two(__lo2, __hi2);
234 
235  const _CharT* __p = __one.c_str();
236  const _CharT* __pend = __one.data() + __one.length();
237  const _CharT* __q = __two.c_str();
238  const _CharT* __qend = __two.data() + __two.length();
239 
240  // strcoll stops when it sees a nul character so we break
241  // the strings into zero-terminated substrings and pass those
242  // to strcoll.
243  for (;;)
244  {
245  const int __res = _M_compare(__p, __q);
246  if (__res)
247  return __res;
248 
249  __p += char_traits<_CharT>::length(__p);
250  __q += char_traits<_CharT>::length(__q);
251  if (__p == __pend && __q == __qend)
252  return 0;
253  else if (__p == __pend)
254  return -1;
255  else if (__q == __qend)
256  return 1;
257 
258  __p++;
259  __q++;
260  }
261  }
262 
263  template<typename _CharT>
266  do_transform(const _CharT* __lo, const _CharT* __hi) const
267  {
268  string_type __ret;
269 
270  // strxfrm assumes zero-terminated strings so we make a copy
271  const string_type __str(__lo, __hi);
272 
273  const _CharT* __p = __str.c_str();
274  const _CharT* __pend = __str.data() + __str.length();
275 
276  size_t __len = (__hi - __lo) * 2;
277 
278  _CharT* __c = new _CharT[__len];
279 
280  __try
281  {
282  // strxfrm stops when it sees a nul character so we break
283  // the string into zero-terminated substrings and pass those
284  // to strxfrm.
285  for (;;)
286  {
287  // First try a buffer perhaps big enough.
288  size_t __res = _M_transform(__c, __p, __len);
289  // If the buffer was not large enough, try again with the
290  // correct size.
291  if (__res >= __len)
292  {
293  __len = __res + 1;
294  delete [] __c, __c = 0;
295  __c = new _CharT[__len];
296  __res = _M_transform(__c, __p, __len);
297  }
298 
299  __ret.append(__c, __res);
300  __p += char_traits<_CharT>::length(__p);
301  if (__p == __pend)
302  break;
303 
304  __p++;
305  __ret.push_back(_CharT());
306  }
307  }
308  __catch(...)
309  {
310  delete [] __c;
311  __throw_exception_again;
312  }
313 
314  delete [] __c;
315 
316  return __ret;
317  }
318 
319  template<typename _CharT>
320  long
322  do_hash(const _CharT* __lo, const _CharT* __hi) const
323  {
324  unsigned long __val = 0;
325  for (; __lo < __hi; ++__lo)
326  __val =
327  *__lo + ((__val << 7)
328  | (__val >> (__gnu_cxx::__numeric_traits<unsigned long>::
329  __digits - 7)));
330  return static_cast<long>(__val);
331  }
332 
333  // Inhibit implicit instantiations for required instantiations,
334  // which are defined via explicit instantiations elsewhere.
335 #if _GLIBCXX_EXTERN_TEMPLATE
336  extern template class collate<char>;
337  extern template class collate_byname<char>;
338 
339  extern template
340  const collate<char>*
341  __try_use_facet<collate<char> >(const locale&) _GLIBCXX_NOTHROW;
342 
343  extern template
344  const collate<char>&
345  use_facet<collate<char> >(const locale&);
346 
347  extern template
348  bool
349  has_facet<collate<char> >(const locale&);
350 
351 #ifdef _GLIBCXX_USE_WCHAR_T
352  extern template class collate<wchar_t>;
353  extern template class collate_byname<wchar_t>;
354 
355  extern template
356  const collate<wchar_t>*
357  __try_use_facet<collate<wchar_t> >(const locale&) _GLIBCXX_NOTHROW;
358 
359  extern template
360  const collate<wchar_t>&
361  use_facet<collate<wchar_t> >(const locale&);
362 
363  extern template
364  bool
365  has_facet<collate<wchar_t> >(const locale&);
366 #endif
367 #endif
368 
369 _GLIBCXX_END_NAMESPACE_VERSION
370 } // namespace std
371 
372 #endif
ISO C++ entities toplevel namespace is std.
virtual long do_hash(const _CharT *__lo, const _CharT *__hi) const
Return hash of a string.
void push_back(_CharT __c)
Append a single character.
Definition: cow_string.h:1374
Localization functionality base class.The facet class is the base class for a localization feature...
Managing sequences of characters and character-like objects.
Definition: cow_string.h:108
virtual string_type do_transform(const _CharT *__lo, const _CharT *__hi) const
Transform string to comparable form.
Container class for localization functionality.The locale class is first a class wrapper for C librar...
const _CharT * c_str() const noexcept
Return const pointer to null-terminated contents.
Definition: cow_string.h:2249
size_type length() const noexcept
Returns the number of characters in the string, not including any null-termination.
Definition: cow_string.h:920
class collate_byname [22.2.4.2].
const _CharT * data() const noexcept
Return const pointer to contents.
Definition: cow_string.h:2261
bool operator()(const basic_string< _Char, _Traits, _Alloc > &__s1, const basic_string< _Char, _Traits, _Alloc > &__s2) const
Compare two strings according to collate.
locale()
Default constructor.
bool has_facet(const locale &__loc)
Test for the presence of a facet.has_facet tests the locale argument for the presence of the facet ty...
const _Facet & use_facet(const locale &__loc)
Return a facet.use_facet looks for and returns a reference to a facet of type Facet where Facet is th...
Basis for explicit traits specializations.
Definition: char_traits.h:323
basic_string & append(const basic_string &__str)
Append a string to this string.
Definition: cow_string.h:3341
virtual int do_compare(const _CharT *__lo1, const _CharT *__hi1, const _CharT *__lo2, const _CharT *__hi2) const
Compare two strings.
Facet for localized string comparison.
locale combine(const locale &__other) const
Construct locale with another facet.