1 // Locale support (codecvt) -*- C++ -*-
3 // Copyright (C) 2000-2016 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file bits/codecvt.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{locale}
31 // ISO C++ 14882: 22.2.1.5 Template class codecvt
34 // Written by Benjamin Kosnik <bkoz@redhat.com>
39 #pragma GCC system_header
41 namespace std
_GLIBCXX_VISIBILITY(default)
43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
45 /// Empty base class for codecvt facet [22.2.1.5].
59 * @brief Common base for codecvt functions.
61 * This template class provides implementations of the public functions
62 * that forward to the protected virtual functions.
64 * This template also provides abstract stubs for the protected virtual
67 template<typename _InternT
, typename _ExternT
, typename _StateT
>
68 class __codecvt_abstract_base
69 : public locale::facet
, public codecvt_base
73 typedef codecvt_base::result result
;
74 typedef _InternT intern_type
;
75 typedef _ExternT extern_type
;
76 typedef _StateT state_type
;
78 // 22.2.1.5.1 codecvt members
80 * @brief Convert from internal to external character set.
82 * Converts input string of intern_type to output string of
83 * extern_type. This is analogous to wcsrtombs. It does this by
84 * calling codecvt::do_out.
86 * The source and destination character sets are determined by the
87 * facet's locale, internal and external types.
89 * The characters in [from,from_end) are converted and written to
90 * [to,to_end). from_next and to_next are set to point to the
91 * character following the last successfully converted character,
92 * respectively. If the result needed no conversion, from_next and
93 * to_next are not affected.
95 * The @a state argument should be initialized if the input is at the
96 * beginning and carried from a previous call if continuing
97 * conversion. There are no guarantees about how @a state is used.
99 * The result returned is a member of codecvt_base::result. If
100 * all the input is converted, returns codecvt_base::ok. If no
101 * conversion is necessary, returns codecvt_base::noconv. If
102 * the input ends early or there is insufficient space in the
103 * output, returns codecvt_base::partial. Otherwise the
104 * conversion failed and codecvt_base::error is returned.
106 * @param __state Persistent conversion state data.
107 * @param __from Start of input.
108 * @param __from_end End of input.
109 * @param __from_next Returns start of unconverted data.
110 * @param __to Start of output buffer.
111 * @param __to_end End of output buffer.
112 * @param __to_next Returns start of unused output area.
113 * @return codecvt_base::result.
116 out(state_type
& __state
, const intern_type
* __from
,
117 const intern_type
* __from_end
, const intern_type
*& __from_next
,
118 extern_type
* __to
, extern_type
* __to_end
,
119 extern_type
*& __to_next
) const
121 return this->do_out(__state
, __from
, __from_end
, __from_next
,
122 __to
, __to_end
, __to_next
);
126 * @brief Reset conversion state.
128 * Writes characters to output that would restore @a state to initial
129 * conditions. The idea is that if a partial conversion occurs, then
130 * the converting the characters written by this function would leave
131 * the state in initial conditions, rather than partial conversion
132 * state. It does this by calling codecvt::do_unshift().
134 * For example, if 4 external characters always converted to 1 internal
135 * character, and input to in() had 6 external characters with state
136 * saved, this function would write two characters to the output and
137 * set the state to initialized conditions.
139 * The source and destination character sets are determined by the
140 * facet's locale, internal and external types.
142 * The result returned is a member of codecvt_base::result. If the
143 * state could be reset and data written, returns codecvt_base::ok. If
144 * no conversion is necessary, returns codecvt_base::noconv. If the
145 * output has insufficient space, returns codecvt_base::partial.
146 * Otherwise the reset failed and codecvt_base::error is returned.
148 * @param __state Persistent conversion state data.
149 * @param __to Start of output buffer.
150 * @param __to_end End of output buffer.
151 * @param __to_next Returns start of unused output area.
152 * @return codecvt_base::result.
155 unshift(state_type
& __state
, extern_type
* __to
, extern_type
* __to_end
,
156 extern_type
*& __to_next
) const
157 { return this->do_unshift(__state
, __to
,__to_end
,__to_next
); }
160 * @brief Convert from external to internal character set.
162 * Converts input string of extern_type to output string of
163 * intern_type. This is analogous to mbsrtowcs. It does this by
164 * calling codecvt::do_in.
166 * The source and destination character sets are determined by the
167 * facet's locale, internal and external types.
169 * The characters in [from,from_end) are converted and written to
170 * [to,to_end). from_next and to_next are set to point to the
171 * character following the last successfully converted character,
172 * respectively. If the result needed no conversion, from_next and
173 * to_next are not affected.
175 * The @a state argument should be initialized if the input is at the
176 * beginning and carried from a previous call if continuing
177 * conversion. There are no guarantees about how @a state is used.
179 * The result returned is a member of codecvt_base::result. If
180 * all the input is converted, returns codecvt_base::ok. If no
181 * conversion is necessary, returns codecvt_base::noconv. If
182 * the input ends early or there is insufficient space in the
183 * output, returns codecvt_base::partial. Otherwise the
184 * conversion failed and codecvt_base::error is returned.
186 * @param __state Persistent conversion state data.
187 * @param __from Start of input.
188 * @param __from_end End of input.
189 * @param __from_next Returns start of unconverted data.
190 * @param __to Start of output buffer.
191 * @param __to_end End of output buffer.
192 * @param __to_next Returns start of unused output area.
193 * @return codecvt_base::result.
196 in(state_type
& __state
, const extern_type
* __from
,
197 const extern_type
* __from_end
, const extern_type
*& __from_next
,
198 intern_type
* __to
, intern_type
* __to_end
,
199 intern_type
*& __to_next
) const
201 return this->do_in(__state
, __from
, __from_end
, __from_next
,
202 __to
, __to_end
, __to_next
);
206 encoding() const throw()
207 { return this->do_encoding(); }
210 always_noconv() const throw()
211 { return this->do_always_noconv(); }
214 length(state_type
& __state
, const extern_type
* __from
,
215 const extern_type
* __end
, size_t __max
) const
216 { return this->do_length(__state
, __from
, __end
, __max
); }
219 max_length() const throw()
220 { return this->do_max_length(); }
224 __codecvt_abstract_base(size_t __refs
= 0) : locale::facet(__refs
) { }
227 ~__codecvt_abstract_base() { }
230 * @brief Convert from internal to external character set.
232 * Converts input string of intern_type to output string of
233 * extern_type. This function is a hook for derived classes to change
234 * the value returned. @see out for more information.
237 do_out(state_type
& __state
, const intern_type
* __from
,
238 const intern_type
* __from_end
, const intern_type
*& __from_next
,
239 extern_type
* __to
, extern_type
* __to_end
,
240 extern_type
*& __to_next
) const = 0;
243 do_unshift(state_type
& __state
, extern_type
* __to
,
244 extern_type
* __to_end
, extern_type
*& __to_next
) const = 0;
247 do_in(state_type
& __state
, const extern_type
* __from
,
248 const extern_type
* __from_end
, const extern_type
*& __from_next
,
249 intern_type
* __to
, intern_type
* __to_end
,
250 intern_type
*& __to_next
) const = 0;
253 do_encoding() const throw() = 0;
256 do_always_noconv() const throw() = 0;
259 do_length(state_type
&, const extern_type
* __from
,
260 const extern_type
* __end
, size_t __max
) const = 0;
263 do_max_length() const throw() = 0;
267 * @brief Primary class template codecvt.
270 * NB: Generic, mostly useless implementation.
273 template<typename _InternT
, typename _ExternT
, typename _StateT
>
275 : public __codecvt_abstract_base
<_InternT
, _ExternT
, _StateT
>
279 typedef codecvt_base::result result
;
280 typedef _InternT intern_type
;
281 typedef _ExternT extern_type
;
282 typedef _StateT state_type
;
285 __c_locale _M_c_locale_codecvt
;
288 static locale::id id
;
291 codecvt(size_t __refs
= 0)
292 : __codecvt_abstract_base
<_InternT
, _ExternT
, _StateT
> (__refs
),
293 _M_c_locale_codecvt(0)
297 codecvt(__c_locale __cloc
, size_t __refs
= 0);
304 do_out(state_type
& __state
, const intern_type
* __from
,
305 const intern_type
* __from_end
, const intern_type
*& __from_next
,
306 extern_type
* __to
, extern_type
* __to_end
,
307 extern_type
*& __to_next
) const;
310 do_unshift(state_type
& __state
, extern_type
* __to
,
311 extern_type
* __to_end
, extern_type
*& __to_next
) const;
314 do_in(state_type
& __state
, const extern_type
* __from
,
315 const extern_type
* __from_end
, const extern_type
*& __from_next
,
316 intern_type
* __to
, intern_type
* __to_end
,
317 intern_type
*& __to_next
) const;
320 do_encoding() const throw();
323 do_always_noconv() const throw();
326 do_length(state_type
&, const extern_type
* __from
,
327 const extern_type
* __end
, size_t __max
) const;
330 do_max_length() const throw();
333 template<typename _InternT
, typename _ExternT
, typename _StateT
>
334 locale::id codecvt
<_InternT
, _ExternT
, _StateT
>::id
;
336 /// class codecvt<char, char, mbstate_t> specialization.
338 class codecvt
<char, char, mbstate_t>
339 : public __codecvt_abstract_base
<char, char, mbstate_t>
341 friend class messages
<char>;
345 typedef char intern_type
;
346 typedef char extern_type
;
347 typedef mbstate_t state_type
;
350 __c_locale _M_c_locale_codecvt
;
353 static locale::id id
;
356 codecvt(size_t __refs
= 0);
359 codecvt(__c_locale __cloc
, size_t __refs
= 0);
366 do_out(state_type
& __state
, const intern_type
* __from
,
367 const intern_type
* __from_end
, const intern_type
*& __from_next
,
368 extern_type
* __to
, extern_type
* __to_end
,
369 extern_type
*& __to_next
) const;
372 do_unshift(state_type
& __state
, extern_type
* __to
,
373 extern_type
* __to_end
, extern_type
*& __to_next
) const;
376 do_in(state_type
& __state
, const extern_type
* __from
,
377 const extern_type
* __from_end
, const extern_type
*& __from_next
,
378 intern_type
* __to
, intern_type
* __to_end
,
379 intern_type
*& __to_next
) const;
382 do_encoding() const throw();
385 do_always_noconv() const throw();
388 do_length(state_type
&, const extern_type
* __from
,
389 const extern_type
* __end
, size_t __max
) const;
392 do_max_length() const throw();
395 #ifdef _GLIBCXX_USE_WCHAR_T
396 /** @brief Class codecvt<wchar_t, char, mbstate_t> specialization.
398 * Converts between narrow and wide characters in the native character set
401 class codecvt
<wchar_t, char, mbstate_t>
402 : public __codecvt_abstract_base
<wchar_t, char, mbstate_t>
404 friend class messages
<wchar_t>;
408 typedef wchar_t intern_type
;
409 typedef char extern_type
;
410 typedef mbstate_t state_type
;
413 __c_locale _M_c_locale_codecvt
;
416 static locale::id id
;
419 codecvt(size_t __refs
= 0);
422 codecvt(__c_locale __cloc
, size_t __refs
= 0);
429 do_out(state_type
& __state
, const intern_type
* __from
,
430 const intern_type
* __from_end
, const intern_type
*& __from_next
,
431 extern_type
* __to
, extern_type
* __to_end
,
432 extern_type
*& __to_next
) const;
435 do_unshift(state_type
& __state
,
436 extern_type
* __to
, extern_type
* __to_end
,
437 extern_type
*& __to_next
) const;
440 do_in(state_type
& __state
,
441 const extern_type
* __from
, const extern_type
* __from_end
,
442 const extern_type
*& __from_next
,
443 intern_type
* __to
, intern_type
* __to_end
,
444 intern_type
*& __to_next
) const;
447 int do_encoding() const throw();
450 bool do_always_noconv() const throw();
453 int do_length(state_type
&, const extern_type
* __from
,
454 const extern_type
* __end
, size_t __max
) const;
457 do_max_length() const throw();
459 #endif //_GLIBCXX_USE_WCHAR_T
461 #if __cplusplus >= 201103L
462 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
463 /** @brief Class codecvt<char16_t, char, mbstate_t> specialization.
465 * Converts between UTF-16 and UTF-8.
468 class codecvt
<char16_t
, char, mbstate_t>
469 : public __codecvt_abstract_base
<char16_t
, char, mbstate_t>
473 typedef char16_t intern_type
;
474 typedef char extern_type
;
475 typedef mbstate_t state_type
;
478 static locale::id id
;
481 codecvt(size_t __refs
= 0)
482 : __codecvt_abstract_base
<char16_t
, char, mbstate_t>(__refs
) { }
489 do_out(state_type
& __state
, const intern_type
* __from
,
490 const intern_type
* __from_end
, const intern_type
*& __from_next
,
491 extern_type
* __to
, extern_type
* __to_end
,
492 extern_type
*& __to_next
) const;
495 do_unshift(state_type
& __state
,
496 extern_type
* __to
, extern_type
* __to_end
,
497 extern_type
*& __to_next
) const;
500 do_in(state_type
& __state
,
501 const extern_type
* __from
, const extern_type
* __from_end
,
502 const extern_type
*& __from_next
,
503 intern_type
* __to
, intern_type
* __to_end
,
504 intern_type
*& __to_next
) const;
507 int do_encoding() const throw();
510 bool do_always_noconv() const throw();
513 int do_length(state_type
&, const extern_type
* __from
,
514 const extern_type
* __end
, size_t __max
) const;
517 do_max_length() const throw();
520 /** @brief Class codecvt<char32_t, char, mbstate_t> specialization.
522 * Converts between UTF-32 and UTF-8.
525 class codecvt
<char32_t
, char, mbstate_t>
526 : public __codecvt_abstract_base
<char32_t
, char, mbstate_t>
530 typedef char32_t intern_type
;
531 typedef char extern_type
;
532 typedef mbstate_t state_type
;
535 static locale::id id
;
538 codecvt(size_t __refs
= 0)
539 : __codecvt_abstract_base
<char32_t
, char, mbstate_t>(__refs
) { }
546 do_out(state_type
& __state
, const intern_type
* __from
,
547 const intern_type
* __from_end
, const intern_type
*& __from_next
,
548 extern_type
* __to
, extern_type
* __to_end
,
549 extern_type
*& __to_next
) const;
552 do_unshift(state_type
& __state
,
553 extern_type
* __to
, extern_type
* __to_end
,
554 extern_type
*& __to_next
) const;
557 do_in(state_type
& __state
,
558 const extern_type
* __from
, const extern_type
* __from_end
,
559 const extern_type
*& __from_next
,
560 intern_type
* __to
, intern_type
* __to_end
,
561 intern_type
*& __to_next
) const;
564 int do_encoding() const throw();
567 bool do_always_noconv() const throw();
570 int do_length(state_type
&, const extern_type
* __from
,
571 const extern_type
* __end
, size_t __max
) const;
574 do_max_length() const throw();
577 #endif // _GLIBCXX_USE_C99_STDINT_TR1
580 /// class codecvt_byname [22.2.1.6].
581 template<typename _InternT
, typename _ExternT
, typename _StateT
>
582 class codecvt_byname
: public codecvt
<_InternT
, _ExternT
, _StateT
>
586 codecvt_byname(const char* __s
, size_t __refs
= 0)
587 : codecvt
<_InternT
, _ExternT
, _StateT
>(__refs
)
589 if (__builtin_strcmp(__s
, "C") != 0
590 && __builtin_strcmp(__s
, "POSIX") != 0)
592 this->_S_destroy_c_locale(this->_M_c_locale_codecvt
);
593 this->_S_create_c_locale(this->_M_c_locale_codecvt
, __s
);
597 #if __cplusplus >= 201103L
599 codecvt_byname(const string
& __s
, size_t __refs
= 0)
600 : codecvt_byname(__s
.c_str(), __refs
) { }
605 ~codecvt_byname() { }
608 #if __cplusplus >= 201103L && defined(_GLIBCXX_USE_C99_STDINT_TR1)
610 class codecvt_byname
<char16_t
, char, mbstate_t>
611 : public codecvt
<char16_t
, char, mbstate_t>
615 codecvt_byname(const char* __s
, size_t __refs
= 0)
616 : codecvt
<char16_t
, char, mbstate_t>(__refs
) { }
619 codecvt_byname(const string
& __s
, size_t __refs
= 0)
620 : codecvt_byname(__s
.c_str(), __refs
) { }
624 ~codecvt_byname() { }
628 class codecvt_byname
<char32_t
, char, mbstate_t>
629 : public codecvt
<char32_t
, char, mbstate_t>
633 codecvt_byname(const char* __s
, size_t __refs
= 0)
634 : codecvt
<char32_t
, char, mbstate_t>(__refs
) { }
637 codecvt_byname(const string
& __s
, size_t __refs
= 0)
638 : codecvt_byname(__s
.c_str(), __refs
) { }
642 ~codecvt_byname() { }
646 // Inhibit implicit instantiations for required instantiations,
647 // which are defined via explicit instantiations elsewhere.
648 #if _GLIBCXX_EXTERN_TEMPLATE
649 extern template class codecvt_byname
<char, char, mbstate_t>;
652 const codecvt
<char, char, mbstate_t>&
653 use_facet
<codecvt
<char, char, mbstate_t> >(const locale
&);
657 has_facet
<codecvt
<char, char, mbstate_t> >(const locale
&);
659 #ifdef _GLIBCXX_USE_WCHAR_T
660 extern template class codecvt_byname
<wchar_t, char, mbstate_t>;
663 const codecvt
<wchar_t, char, mbstate_t>&
664 use_facet
<codecvt
<wchar_t, char, mbstate_t> >(const locale
&);
668 has_facet
<codecvt
<wchar_t, char, mbstate_t> >(const locale
&);
671 #if __cplusplus >= 201103L && defined(_GLIBCXX_USE_C99_STDINT_TR1)
672 extern template class codecvt_byname
<char16_t
, char, mbstate_t>;
673 extern template class codecvt_byname
<char32_t
, char, mbstate_t>;
678 _GLIBCXX_END_NAMESPACE_VERSION