libstdc++
locale_classes.tcc
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1 // Locale support -*- C++ -*-
2 
3 // Copyright (C) 2007-2017 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  /**
91  * @brief Test for the presence of a facet.
92  * @ingroup locales
93  *
94  * has_facet tests the locale argument for the presence of the facet type
95  * provided as the template parameter. Facets derived from the facet
96  * parameter will also return true.
97  *
98  * @tparam _Facet The facet type to test the presence of.
99  * @param __loc The locale to test.
100  * @return true if @p __loc contains a facet of type _Facet, else false.
101  */
102  template<typename _Facet>
103  bool
104  has_facet(const locale& __loc) throw()
105  {
106  const size_t __i = _Facet::id._M_id();
107  const locale::facet** __facets = __loc._M_impl->_M_facets;
108  return (__i < __loc._M_impl->_M_facets_size
109 #if __cpp_rtti
110  && dynamic_cast<const _Facet*>(__facets[__i]));
111 #else
112  && static_cast<const _Facet*>(__facets[__i]));
113 #endif
114  }
115 
116  /**
117  * @brief Return a facet.
118  * @ingroup locales
119  *
120  * use_facet looks for and returns a reference to a facet of type Facet
121  * where Facet is the template parameter. If has_facet(locale) is true,
122  * there is a suitable facet to return. It throws std::bad_cast if the
123  * locale doesn't contain a facet of type Facet.
124  *
125  * @tparam _Facet The facet type to access.
126  * @param __loc The locale to use.
127  * @return Reference to facet of type Facet.
128  * @throw std::bad_cast if @p __loc doesn't contain a facet of type _Facet.
129  */
130  template<typename _Facet>
131  const _Facet&
132  use_facet(const locale& __loc)
133  {
134  const size_t __i = _Facet::id._M_id();
135  const locale::facet** __facets = __loc._M_impl->_M_facets;
136  if (__i >= __loc._M_impl->_M_facets_size || !__facets[__i])
137  __throw_bad_cast();
138 #if __cpp_rtti
139  return dynamic_cast<const _Facet&>(*__facets[__i]);
140 #else
141  return static_cast<const _Facet&>(*__facets[__i]);
142 #endif
143  }
144 
145 
146  // Generic version does nothing.
147  template<typename _CharT>
148  int
149  collate<_CharT>::_M_compare(const _CharT*, const _CharT*) const throw ()
150  { return 0; }
151 
152  // Generic version does nothing.
153  template<typename _CharT>
154  size_t
155  collate<_CharT>::_M_transform(_CharT*, const _CharT*, size_t) const throw ()
156  { return 0; }
157 
158  template<typename _CharT>
159  int
161  do_compare(const _CharT* __lo1, const _CharT* __hi1,
162  const _CharT* __lo2, const _CharT* __hi2) const
163  {
164  // strcoll assumes zero-terminated strings so we make a copy
165  // and then put a zero at the end.
166  const string_type __one(__lo1, __hi1);
167  const string_type __two(__lo2, __hi2);
168 
169  const _CharT* __p = __one.c_str();
170  const _CharT* __pend = __one.data() + __one.length();
171  const _CharT* __q = __two.c_str();
172  const _CharT* __qend = __two.data() + __two.length();
173 
174  // strcoll stops when it sees a nul character so we break
175  // the strings into zero-terminated substrings and pass those
176  // to strcoll.
177  for (;;)
178  {
179  const int __res = _M_compare(__p, __q);
180  if (__res)
181  return __res;
182 
183  __p += char_traits<_CharT>::length(__p);
184  __q += char_traits<_CharT>::length(__q);
185  if (__p == __pend && __q == __qend)
186  return 0;
187  else if (__p == __pend)
188  return -1;
189  else if (__q == __qend)
190  return 1;
191 
192  __p++;
193  __q++;
194  }
195  }
196 
197  template<typename _CharT>
200  do_transform(const _CharT* __lo, const _CharT* __hi) const
201  {
202  string_type __ret;
203 
204  // strxfrm assumes zero-terminated strings so we make a copy
205  const string_type __str(__lo, __hi);
206 
207  const _CharT* __p = __str.c_str();
208  const _CharT* __pend = __str.data() + __str.length();
209 
210  size_t __len = (__hi - __lo) * 2;
211 
212  _CharT* __c = new _CharT[__len];
213 
214  __try
215  {
216  // strxfrm stops when it sees a nul character so we break
217  // the string into zero-terminated substrings and pass those
218  // to strxfrm.
219  for (;;)
220  {
221  // First try a buffer perhaps big enough.
222  size_t __res = _M_transform(__c, __p, __len);
223  // If the buffer was not large enough, try again with the
224  // correct size.
225  if (__res >= __len)
226  {
227  __len = __res + 1;
228  delete [] __c, __c = 0;
229  __c = new _CharT[__len];
230  __res = _M_transform(__c, __p, __len);
231  }
232 
233  __ret.append(__c, __res);
234  __p += char_traits<_CharT>::length(__p);
235  if (__p == __pend)
236  break;
237 
238  __p++;
239  __ret.push_back(_CharT());
240  }
241  }
242  __catch(...)
243  {
244  delete [] __c;
245  __throw_exception_again;
246  }
247 
248  delete [] __c;
249 
250  return __ret;
251  }
252 
253  template<typename _CharT>
254  long
256  do_hash(const _CharT* __lo, const _CharT* __hi) const
257  {
258  unsigned long __val = 0;
259  for (; __lo < __hi; ++__lo)
260  __val =
261  *__lo + ((__val << 7)
262  | (__val >> (__gnu_cxx::__numeric_traits<unsigned long>::
263  __digits - 7)));
264  return static_cast<long>(__val);
265  }
266 
267  // Inhibit implicit instantiations for required instantiations,
268  // which are defined via explicit instantiations elsewhere.
269 #if _GLIBCXX_EXTERN_TEMPLATE
270  extern template class collate<char>;
271  extern template class collate_byname<char>;
272 
273  extern template
274  const collate<char>&
275  use_facet<collate<char> >(const locale&);
276 
277  extern template
278  bool
279  has_facet<collate<char> >(const locale&);
280 
281 #ifdef _GLIBCXX_USE_WCHAR_T
282  extern template class collate<wchar_t>;
283  extern template class collate_byname<wchar_t>;
284 
285  extern template
286  const collate<wchar_t>&
287  use_facet<collate<wchar_t> >(const locale&);
288 
289  extern template
290  bool
291  has_facet<collate<wchar_t> >(const locale&);
292 #endif
293 #endif
294 
295 _GLIBCXX_END_NAMESPACE_VERSION
296 } // namespace std
297 
298 #endif
bool operator()(const basic_string< _Char, _Traits, _Alloc > &__s1, const basic_string< _Char, _Traits, _Alloc > &__s2) const
Compare two strings according to collate.
void push_back(_CharT __c)
Append a single character.
Facet for localized string comparison.
Localization functionality base class.The facet class is the base class for a localization feature...
ISO C++ entities toplevel namespace is std.
locale()
Default constructor.
const _CharT * data() const noexcept
Return const pointer to contents.
friend bool has_facet(const locale &)
Test for the presence of a facet.has_facet tests the locale argument for the presence of the facet ty...
virtual string_type do_transform(const _CharT *__lo, const _CharT *__hi) const
Transform string to comparable form.
size_type length() const noexcept
Returns the number of characters in the string, not including any null-termination.
Managing sequences of characters and character-like objects.
basic_string & append(const basic_string &__str)
Append a string to this string.
const _CharT * c_str() const noexcept
Return const pointer to null-terminated contents.
Container class for localization functionality.The locale class is first a class wrapper for C librar...
Basis for explicit traits specializations.
Definition: char_traits.h:269
friend const _Facet & use_facet(const locale &)
Return a facet.use_facet looks for and returns a reference to a facet of type Facet where Facet is th...
class collate_byname [22.2.4.2].
virtual long do_hash(const _CharT *__lo, const _CharT *__hi) const
Return hash of a string.
virtual int do_compare(const _CharT *__lo1, const _CharT *__hi1, const _CharT *__lo2, const _CharT *__hi2) const
Compare two strings.
locale combine(const locale &__other) const
Construct locale with another facet.