libstdc++
char_traits.h
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1 // Character Traits for use by standard string and iostream -*- C++ -*-
2 
3 // Copyright (C) 1997-2019 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/char_traits.h
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{string}
28  */
29 
30 //
31 // ISO C++ 14882: 21 Strings library
32 //
33 
34 #ifndef _CHAR_TRAITS_H
35 #define _CHAR_TRAITS_H 1
36 
37 #pragma GCC system_header
38 
39 #include <bits/stl_algobase.h> // std::copy, std::fill_n
40 #include <bits/postypes.h> // For streampos
41 #include <cwchar> // For WEOF, wmemmove, wmemset, etc.
42 
43 #ifndef _GLIBCXX_ALWAYS_INLINE
44 # define _GLIBCXX_ALWAYS_INLINE inline __attribute__((__always_inline__))
45 #endif
46 
47 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
48 {
49 _GLIBCXX_BEGIN_NAMESPACE_VERSION
50 
51  /**
52  * @brief Mapping from character type to associated types.
53  *
54  * @note This is an implementation class for the generic version
55  * of char_traits. It defines int_type, off_type, pos_type, and
56  * state_type. By default these are unsigned long, streamoff,
57  * streampos, and mbstate_t. Users who need a different set of
58  * types, but who don't need to change the definitions of any function
59  * defined in char_traits, can specialize __gnu_cxx::_Char_types
60  * while leaving __gnu_cxx::char_traits alone. */
61  template<typename _CharT>
62  struct _Char_types
63  {
64  typedef unsigned long int_type;
65  typedef std::streampos pos_type;
66  typedef std::streamoff off_type;
67  typedef std::mbstate_t state_type;
68  };
69 
70 
71  /**
72  * @brief Base class used to implement std::char_traits.
73  *
74  * @note For any given actual character type, this definition is
75  * probably wrong. (Most of the member functions are likely to be
76  * right, but the int_type and state_type typedefs, and the eof()
77  * member function, are likely to be wrong.) The reason this class
78  * exists is so users can specialize it. Classes in namespace std
79  * may not be specialized for fundamental types, but classes in
80  * namespace __gnu_cxx may be.
81  *
82  * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/strings.html#strings.string.character_types
83  * for advice on how to make use of this class for @a unusual character
84  * types. Also, check out include/ext/pod_char_traits.h.
85  */
86  template<typename _CharT>
87  struct char_traits
88  {
89  typedef _CharT char_type;
90  typedef typename _Char_types<_CharT>::int_type int_type;
91  typedef typename _Char_types<_CharT>::pos_type pos_type;
92  typedef typename _Char_types<_CharT>::off_type off_type;
93  typedef typename _Char_types<_CharT>::state_type state_type;
94 
95  static _GLIBCXX14_CONSTEXPR void
96  assign(char_type& __c1, const char_type& __c2)
97  { __c1 = __c2; }
98 
99  static _GLIBCXX_CONSTEXPR bool
100  eq(const char_type& __c1, const char_type& __c2)
101  { return __c1 == __c2; }
102 
103  static _GLIBCXX_CONSTEXPR bool
104  lt(const char_type& __c1, const char_type& __c2)
105  { return __c1 < __c2; }
106 
107  static _GLIBCXX14_CONSTEXPR int
108  compare(const char_type* __s1, const char_type* __s2, std::size_t __n);
109 
110  static _GLIBCXX14_CONSTEXPR std::size_t
111  length(const char_type* __s);
112 
113  static _GLIBCXX14_CONSTEXPR const char_type*
114  find(const char_type* __s, std::size_t __n, const char_type& __a);
115 
116  static char_type*
117  move(char_type* __s1, const char_type* __s2, std::size_t __n);
118 
119  static char_type*
120  copy(char_type* __s1, const char_type* __s2, std::size_t __n);
121 
122  static char_type*
123  assign(char_type* __s, std::size_t __n, char_type __a);
124 
125  static _GLIBCXX_CONSTEXPR char_type
126  to_char_type(const int_type& __c)
127  { return static_cast<char_type>(__c); }
128 
129  static _GLIBCXX_CONSTEXPR int_type
130  to_int_type(const char_type& __c)
131  { return static_cast<int_type>(__c); }
132 
133  static _GLIBCXX_CONSTEXPR bool
134  eq_int_type(const int_type& __c1, const int_type& __c2)
135  { return __c1 == __c2; }
136 
137  static _GLIBCXX_CONSTEXPR int_type
138  eof()
139  { return static_cast<int_type>(_GLIBCXX_STDIO_EOF); }
140 
141  static _GLIBCXX_CONSTEXPR int_type
142  not_eof(const int_type& __c)
143  { return !eq_int_type(__c, eof()) ? __c : to_int_type(char_type()); }
144  };
145 
146  template<typename _CharT>
147  _GLIBCXX14_CONSTEXPR int
149  compare(const char_type* __s1, const char_type* __s2, std::size_t __n)
150  {
151  for (std::size_t __i = 0; __i < __n; ++__i)
152  if (lt(__s1[__i], __s2[__i]))
153  return -1;
154  else if (lt(__s2[__i], __s1[__i]))
155  return 1;
156  return 0;
157  }
158 
159  template<typename _CharT>
160  _GLIBCXX14_CONSTEXPR std::size_t
161  char_traits<_CharT>::
162  length(const char_type* __p)
163  {
164  std::size_t __i = 0;
165  while (!eq(__p[__i], char_type()))
166  ++__i;
167  return __i;
168  }
169 
170  template<typename _CharT>
171  _GLIBCXX14_CONSTEXPR const typename char_traits<_CharT>::char_type*
172  char_traits<_CharT>::
173  find(const char_type* __s, std::size_t __n, const char_type& __a)
174  {
175  for (std::size_t __i = 0; __i < __n; ++__i)
176  if (eq(__s[__i], __a))
177  return __s + __i;
178  return 0;
179  }
180 
181  template<typename _CharT>
182  typename char_traits<_CharT>::char_type*
183  char_traits<_CharT>::
184  move(char_type* __s1, const char_type* __s2, std::size_t __n)
185  {
186  if (__n == 0)
187  return __s1;
188  return static_cast<_CharT*>(__builtin_memmove(__s1, __s2,
189  __n * sizeof(char_type)));
190  }
191 
192  template<typename _CharT>
193  typename char_traits<_CharT>::char_type*
194  char_traits<_CharT>::
195  copy(char_type* __s1, const char_type* __s2, std::size_t __n)
196  {
197  // NB: Inline std::copy so no recursive dependencies.
198  std::copy(__s2, __s2 + __n, __s1);
199  return __s1;
200  }
201 
202  template<typename _CharT>
203  typename char_traits<_CharT>::char_type*
204  char_traits<_CharT>::
205  assign(char_type* __s, std::size_t __n, char_type __a)
206  {
207  // NB: Inline std::fill_n so no recursive dependencies.
208  std::fill_n(__s, __n, __a);
209  return __s;
210  }
211 
212 _GLIBCXX_END_NAMESPACE_VERSION
213 } // namespace
214 
215 namespace std _GLIBCXX_VISIBILITY(default)
216 {
217 _GLIBCXX_BEGIN_NAMESPACE_VERSION
218 
219 #if __cplusplus >= 201703L
220 #define __cpp_lib_constexpr_char_traits 201611
221 
222  /**
223  * @brief Determine whether the characters of a NULL-terminated
224  * string are known at compile time.
225  * @param __s The string.
226  *
227  * Assumes that _CharT is a built-in character type.
228  */
229  template<typename _CharT>
230  static _GLIBCXX_ALWAYS_INLINE constexpr bool
231  __constant_string_p(const _CharT* __s)
232  {
233 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
234  (void) __s;
235  // In constexpr contexts all strings should be constant.
236  return __builtin_is_constant_evaluated();
237 #else
238  while (__builtin_constant_p(*__s) && *__s)
239  __s++;
240  return __builtin_constant_p(*__s);
241 #endif
242  }
243 
244  /**
245  * @brief Determine whether the characters of a character array are
246  * known at compile time.
247  * @param __a The character array.
248  * @param __n Number of characters.
249  *
250  * Assumes that _CharT is a built-in character type.
251  */
252  template<typename _CharT>
253  static _GLIBCXX_ALWAYS_INLINE constexpr bool
254  __constant_char_array_p(const _CharT* __a, size_t __n)
255  {
256 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
257  (void) __a;
258  (void) __n;
259  // In constexpr contexts all character arrays should be constant.
260  return __builtin_is_constant_evaluated();
261 #else
262  size_t __i = 0;
263  while (__builtin_constant_p(__a[__i]) && __i < __n)
264  __i++;
265  return __i == __n;
266 #endif
267  }
268 #endif
269 
270  // 21.1
271  /**
272  * @brief Basis for explicit traits specializations.
273  *
274  * @note For any given actual character type, this definition is
275  * probably wrong. Since this is just a thin wrapper around
276  * __gnu_cxx::char_traits, it is possible to achieve a more
277  * appropriate definition by specializing __gnu_cxx::char_traits.
278  *
279  * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/strings.html#strings.string.character_types
280  * for advice on how to make use of this class for @a unusual character
281  * types. Also, check out include/ext/pod_char_traits.h.
282  */
283  template<class _CharT>
284  struct char_traits : public __gnu_cxx::char_traits<_CharT>
285  { };
286 
287 
288  /// 21.1.3.1 char_traits specializations
289  template<>
290  struct char_traits<char>
291  {
292  typedef char char_type;
293  typedef int int_type;
294  typedef streampos pos_type;
295  typedef streamoff off_type;
296  typedef mbstate_t state_type;
297 
298  static _GLIBCXX17_CONSTEXPR void
299  assign(char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
300  { __c1 = __c2; }
301 
302  static _GLIBCXX_CONSTEXPR bool
303  eq(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
304  { return __c1 == __c2; }
305 
306  static _GLIBCXX_CONSTEXPR bool
307  lt(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
308  {
309  // LWG 467.
310  return (static_cast<unsigned char>(__c1)
311  < static_cast<unsigned char>(__c2));
312  }
313 
314  static _GLIBCXX17_CONSTEXPR int
315  compare(const char_type* __s1, const char_type* __s2, size_t __n)
316  {
317 #if __cplusplus >= 201703L
318  if (__builtin_constant_p(__n)
319  && __constant_char_array_p(__s1, __n)
320  && __constant_char_array_p(__s2, __n))
321  return __gnu_cxx::char_traits<char_type>::compare(__s1, __s2, __n);
322 #endif
323  if (__n == 0)
324  return 0;
325  return __builtin_memcmp(__s1, __s2, __n);
326  }
327 
328  static _GLIBCXX17_CONSTEXPR size_t
329  length(const char_type* __s)
330  {
331 #if __cplusplus >= 201703L
332  if (__constant_string_p(__s))
334 #endif
335  return __builtin_strlen(__s);
336  }
337 
338  static _GLIBCXX17_CONSTEXPR const char_type*
339  find(const char_type* __s, size_t __n, const char_type& __a)
340  {
341 #if __cplusplus >= 201703L
342  if (__builtin_constant_p(__n)
343  && __builtin_constant_p(__a)
344  && __constant_char_array_p(__s, __n))
345  return __gnu_cxx::char_traits<char_type>::find(__s, __n, __a);
346 #endif
347  if (__n == 0)
348  return 0;
349  return static_cast<const char_type*>(__builtin_memchr(__s, __a, __n));
350  }
351 
352  static char_type*
353  move(char_type* __s1, const char_type* __s2, size_t __n)
354  {
355  if (__n == 0)
356  return __s1;
357  return static_cast<char_type*>(__builtin_memmove(__s1, __s2, __n));
358  }
359 
360  static char_type*
361  copy(char_type* __s1, const char_type* __s2, size_t __n)
362  {
363  if (__n == 0)
364  return __s1;
365  return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
366  }
367 
368  static char_type*
369  assign(char_type* __s, size_t __n, char_type __a)
370  {
371  if (__n == 0)
372  return __s;
373  return static_cast<char_type*>(__builtin_memset(__s, __a, __n));
374  }
375 
376  static _GLIBCXX_CONSTEXPR char_type
377  to_char_type(const int_type& __c) _GLIBCXX_NOEXCEPT
378  { return static_cast<char_type>(__c); }
379 
380  // To keep both the byte 0xff and the eof symbol 0xffffffff
381  // from ending up as 0xffffffff.
382  static _GLIBCXX_CONSTEXPR int_type
383  to_int_type(const char_type& __c) _GLIBCXX_NOEXCEPT
384  { return static_cast<int_type>(static_cast<unsigned char>(__c)); }
385 
386  static _GLIBCXX_CONSTEXPR bool
387  eq_int_type(const int_type& __c1, const int_type& __c2) _GLIBCXX_NOEXCEPT
388  { return __c1 == __c2; }
389 
390  static _GLIBCXX_CONSTEXPR int_type
391  eof() _GLIBCXX_NOEXCEPT
392  { return static_cast<int_type>(_GLIBCXX_STDIO_EOF); }
393 
394  static _GLIBCXX_CONSTEXPR int_type
395  not_eof(const int_type& __c) _GLIBCXX_NOEXCEPT
396  { return (__c == eof()) ? 0 : __c; }
397  };
398 
399 
400 #ifdef _GLIBCXX_USE_WCHAR_T
401  /// 21.1.3.2 char_traits specializations
402  template<>
403  struct char_traits<wchar_t>
404  {
405  typedef wchar_t char_type;
406  typedef wint_t int_type;
407  typedef streamoff off_type;
408  typedef wstreampos pos_type;
409  typedef mbstate_t state_type;
410 
411  static _GLIBCXX17_CONSTEXPR void
412  assign(char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
413  { __c1 = __c2; }
414 
415  static _GLIBCXX_CONSTEXPR bool
416  eq(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
417  { return __c1 == __c2; }
418 
419  static _GLIBCXX_CONSTEXPR bool
420  lt(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
421  { return __c1 < __c2; }
422 
423  static _GLIBCXX17_CONSTEXPR int
424  compare(const char_type* __s1, const char_type* __s2, size_t __n)
425  {
426 #if __cplusplus >= 201703L
427  if (__builtin_constant_p(__n)
428  && __constant_char_array_p(__s1, __n)
429  && __constant_char_array_p(__s2, __n))
430  return __gnu_cxx::char_traits<char_type>::compare(__s1, __s2, __n);
431 #endif
432  if (__n == 0)
433  return 0;
434  else
435  return wmemcmp(__s1, __s2, __n);
436  }
437 
438  static _GLIBCXX17_CONSTEXPR size_t
439  length(const char_type* __s)
440  {
441 #if __cplusplus >= 201703L
442  if (__constant_string_p(__s))
444  else
445 #endif
446  return wcslen(__s);
447  }
448 
449  static _GLIBCXX17_CONSTEXPR const char_type*
450  find(const char_type* __s, size_t __n, const char_type& __a)
451  {
452 #if __cplusplus >= 201703L
453  if (__builtin_constant_p(__n)
454  && __builtin_constant_p(__a)
455  && __constant_char_array_p(__s, __n))
456  return __gnu_cxx::char_traits<char_type>::find(__s, __n, __a);
457 #endif
458  if (__n == 0)
459  return 0;
460  else
461  return wmemchr(__s, __a, __n);
462  }
463 
464  static char_type*
465  move(char_type* __s1, const char_type* __s2, size_t __n)
466  {
467  if (__n == 0)
468  return __s1;
469  return wmemmove(__s1, __s2, __n);
470  }
471 
472  static char_type*
473  copy(char_type* __s1, const char_type* __s2, size_t __n)
474  {
475  if (__n == 0)
476  return __s1;
477  return wmemcpy(__s1, __s2, __n);
478  }
479 
480  static char_type*
481  assign(char_type* __s, size_t __n, char_type __a)
482  {
483  if (__n == 0)
484  return __s;
485  return wmemset(__s, __a, __n);
486  }
487 
488  static _GLIBCXX_CONSTEXPR char_type
489  to_char_type(const int_type& __c) _GLIBCXX_NOEXCEPT
490  { return char_type(__c); }
491 
492  static _GLIBCXX_CONSTEXPR int_type
493  to_int_type(const char_type& __c) _GLIBCXX_NOEXCEPT
494  { return int_type(__c); }
495 
496  static _GLIBCXX_CONSTEXPR bool
497  eq_int_type(const int_type& __c1, const int_type& __c2) _GLIBCXX_NOEXCEPT
498  { return __c1 == __c2; }
499 
500  static _GLIBCXX_CONSTEXPR int_type
501  eof() _GLIBCXX_NOEXCEPT
502  { return static_cast<int_type>(WEOF); }
503 
504  static _GLIBCXX_CONSTEXPR int_type
505  not_eof(const int_type& __c) _GLIBCXX_NOEXCEPT
506  { return eq_int_type(__c, eof()) ? 0 : __c; }
507  };
508 #endif //_GLIBCXX_USE_WCHAR_T
509 
510 _GLIBCXX_END_NAMESPACE_VERSION
511 } // namespace
512 
513 #if __cplusplus >= 201103L
514 
515 #include <cstdint>
516 
517 namespace std _GLIBCXX_VISIBILITY(default)
518 {
519 _GLIBCXX_BEGIN_NAMESPACE_VERSION
520 
521  template<>
522  struct char_traits<char16_t>
523  {
524  typedef char16_t char_type;
525 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
526  typedef uint_least16_t int_type;
527 #elif defined __UINT_LEAST16_TYPE__
528  typedef __UINT_LEAST16_TYPE__ int_type;
529 #else
530  typedef make_unsigned<char16_t>::type int_type;
531 #endif
532  typedef streamoff off_type;
533  typedef u16streampos pos_type;
534  typedef mbstate_t state_type;
535 
536  static _GLIBCXX17_CONSTEXPR void
537  assign(char_type& __c1, const char_type& __c2) noexcept
538  { __c1 = __c2; }
539 
540  static constexpr bool
541  eq(const char_type& __c1, const char_type& __c2) noexcept
542  { return __c1 == __c2; }
543 
544  static constexpr bool
545  lt(const char_type& __c1, const char_type& __c2) noexcept
546  { return __c1 < __c2; }
547 
548  static _GLIBCXX17_CONSTEXPR int
549  compare(const char_type* __s1, const char_type* __s2, size_t __n)
550  {
551  for (size_t __i = 0; __i < __n; ++__i)
552  if (lt(__s1[__i], __s2[__i]))
553  return -1;
554  else if (lt(__s2[__i], __s1[__i]))
555  return 1;
556  return 0;
557  }
558 
559  static _GLIBCXX17_CONSTEXPR size_t
560  length(const char_type* __s)
561  {
562  size_t __i = 0;
563  while (!eq(__s[__i], char_type()))
564  ++__i;
565  return __i;
566  }
567 
568  static _GLIBCXX17_CONSTEXPR const char_type*
569  find(const char_type* __s, size_t __n, const char_type& __a)
570  {
571  for (size_t __i = 0; __i < __n; ++__i)
572  if (eq(__s[__i], __a))
573  return __s + __i;
574  return 0;
575  }
576 
577  static char_type*
578  move(char_type* __s1, const char_type* __s2, size_t __n)
579  {
580  if (__n == 0)
581  return __s1;
582  return (static_cast<char_type*>
583  (__builtin_memmove(__s1, __s2, __n * sizeof(char_type))));
584  }
585 
586  static char_type*
587  copy(char_type* __s1, const char_type* __s2, size_t __n)
588  {
589  if (__n == 0)
590  return __s1;
591  return (static_cast<char_type*>
592  (__builtin_memcpy(__s1, __s2, __n * sizeof(char_type))));
593  }
594 
595  static char_type*
596  assign(char_type* __s, size_t __n, char_type __a)
597  {
598  for (size_t __i = 0; __i < __n; ++__i)
599  assign(__s[__i], __a);
600  return __s;
601  }
602 
603  static constexpr char_type
604  to_char_type(const int_type& __c) noexcept
605  { return char_type(__c); }
606 
607  static constexpr int_type
608  to_int_type(const char_type& __c) noexcept
609  { return __c == eof() ? int_type(0xfffd) : int_type(__c); }
610 
611  static constexpr bool
612  eq_int_type(const int_type& __c1, const int_type& __c2) noexcept
613  { return __c1 == __c2; }
614 
615  static constexpr int_type
616  eof() noexcept
617  { return static_cast<int_type>(-1); }
618 
619  static constexpr int_type
620  not_eof(const int_type& __c) noexcept
621  { return eq_int_type(__c, eof()) ? 0 : __c; }
622  };
623 
624  template<>
625  struct char_traits<char32_t>
626  {
627  typedef char32_t char_type;
628 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
629  typedef uint_least32_t int_type;
630 #elif defined __UINT_LEAST32_TYPE__
631  typedef __UINT_LEAST32_TYPE__ int_type;
632 #else
633  typedef make_unsigned<char32_t>::type int_type;
634 #endif
635  typedef streamoff off_type;
636  typedef u32streampos pos_type;
637  typedef mbstate_t state_type;
638 
639  static _GLIBCXX17_CONSTEXPR void
640  assign(char_type& __c1, const char_type& __c2) noexcept
641  { __c1 = __c2; }
642 
643  static constexpr bool
644  eq(const char_type& __c1, const char_type& __c2) noexcept
645  { return __c1 == __c2; }
646 
647  static constexpr bool
648  lt(const char_type& __c1, const char_type& __c2) noexcept
649  { return __c1 < __c2; }
650 
651  static _GLIBCXX17_CONSTEXPR int
652  compare(const char_type* __s1, const char_type* __s2, size_t __n)
653  {
654  for (size_t __i = 0; __i < __n; ++__i)
655  if (lt(__s1[__i], __s2[__i]))
656  return -1;
657  else if (lt(__s2[__i], __s1[__i]))
658  return 1;
659  return 0;
660  }
661 
662  static _GLIBCXX17_CONSTEXPR size_t
663  length(const char_type* __s)
664  {
665  size_t __i = 0;
666  while (!eq(__s[__i], char_type()))
667  ++__i;
668  return __i;
669  }
670 
671  static _GLIBCXX17_CONSTEXPR const char_type*
672  find(const char_type* __s, size_t __n, const char_type& __a)
673  {
674  for (size_t __i = 0; __i < __n; ++__i)
675  if (eq(__s[__i], __a))
676  return __s + __i;
677  return 0;
678  }
679 
680  static char_type*
681  move(char_type* __s1, const char_type* __s2, size_t __n)
682  {
683  if (__n == 0)
684  return __s1;
685  return (static_cast<char_type*>
686  (__builtin_memmove(__s1, __s2, __n * sizeof(char_type))));
687  }
688 
689  static char_type*
690  copy(char_type* __s1, const char_type* __s2, size_t __n)
691  {
692  if (__n == 0)
693  return __s1;
694  return (static_cast<char_type*>
695  (__builtin_memcpy(__s1, __s2, __n * sizeof(char_type))));
696  }
697 
698  static char_type*
699  assign(char_type* __s, size_t __n, char_type __a)
700  {
701  for (size_t __i = 0; __i < __n; ++__i)
702  assign(__s[__i], __a);
703  return __s;
704  }
705 
706  static constexpr char_type
707  to_char_type(const int_type& __c) noexcept
708  { return char_type(__c); }
709 
710  static constexpr int_type
711  to_int_type(const char_type& __c) noexcept
712  { return int_type(__c); }
713 
714  static constexpr bool
715  eq_int_type(const int_type& __c1, const int_type& __c2) noexcept
716  { return __c1 == __c2; }
717 
718  static constexpr int_type
719  eof() noexcept
720  { return static_cast<int_type>(-1); }
721 
722  static constexpr int_type
723  not_eof(const int_type& __c) noexcept
724  { return eq_int_type(__c, eof()) ? 0 : __c; }
725  };
726 
727 _GLIBCXX_END_NAMESPACE_VERSION
728 } // namespace
729 
730 #endif // C++11
731 
732 #endif // _CHAR_TRAITS_H
Mapping from character type to associated types.
Definition: char_traits.h:62
Basis for explicit traits specializations.
Definition: char_traits.h:284
ISO C++ entities toplevel namespace is std.
fpos< mbstate_t > u32streampos
File position for char32_t streams.
Definition: postypes.h:242
GNU extensions for public use.
Base class used to implement std::char_traits.
Definition: char_traits.h:87
fpos< mbstate_t > u16streampos
File position for char16_t streams.
Definition: postypes.h:240
_OI fill_n(_OI __first, _Size __n, const _Tp &__value)
Fills the range [first,first+n) with copies of value.
Definition: stl_algobase.h:802
Class representing stream positions.
Definition: postypes.h:112
long long streamoff
Type used by fpos, char_traits<char>, and char_traits<wchar_t>.
Definition: postypes.h:94