libstdc++

locale_classes.tcc
Go to the documentation of this file.
1 // Locale support -*- C++ -*-
2
3 // Copyright (C) 2007-2013 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::
81 operator()(const basic_string<_CharT, _Traits, _Alloc>& __s1,
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 #ifdef __GXX_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 #ifdef __GXX_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
160 collate<_CharT>::
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>
198 typename collate<_CharT>::string_type
199 collate<_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
255 collate<_CharT>::
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