34 #ifndef _CHAR_TRAITS_H 35 #define _CHAR_TRAITS_H 1 37 #pragma GCC system_header 42 #if __cplusplus > 201703L 46 #ifndef _GLIBCXX_ALWAYS_INLINE 47 # define _GLIBCXX_ALWAYS_INLINE inline __attribute__((__always_inline__)) 50 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
52 _GLIBCXX_BEGIN_NAMESPACE_VERSION
64 template<
typename _CharT>
67 typedef unsigned long int_type;
70 typedef std::mbstate_t state_type;
89 template<
typename _CharT>
92 typedef _CharT char_type;
93 typedef typename _Char_types<_CharT>::int_type int_type;
95 typedef typename _Char_types<_CharT>::off_type off_type;
96 typedef typename _Char_types<_CharT>::state_type state_type;
97 #if __cpp_lib_three_way_comparison 98 using comparison_category = std::strong_ordering;
101 static _GLIBCXX14_CONSTEXPR
void 102 assign(char_type& __c1,
const char_type& __c2)
105 static _GLIBCXX_CONSTEXPR
bool 106 eq(
const char_type& __c1,
const char_type& __c2)
107 {
return __c1 == __c2; }
109 static _GLIBCXX_CONSTEXPR
bool 110 lt(
const char_type& __c1,
const char_type& __c2)
111 {
return __c1 < __c2; }
113 static _GLIBCXX14_CONSTEXPR
int 114 compare(
const char_type* __s1,
const char_type* __s2, std::size_t __n);
116 static _GLIBCXX14_CONSTEXPR std::size_t
117 length(
const char_type* __s);
119 static _GLIBCXX14_CONSTEXPR
const char_type*
120 find(
const char_type* __s, std::size_t __n,
const char_type& __a);
122 static _GLIBCXX20_CONSTEXPR char_type*
123 move(char_type* __s1,
const char_type* __s2, std::size_t __n);
125 static _GLIBCXX20_CONSTEXPR char_type*
126 copy(char_type* __s1,
const char_type* __s2, std::size_t __n);
128 static _GLIBCXX20_CONSTEXPR char_type*
129 assign(char_type* __s, std::size_t __n, char_type __a);
131 static _GLIBCXX_CONSTEXPR char_type
132 to_char_type(
const int_type& __c)
133 {
return static_cast<char_type
>(__c); }
135 static _GLIBCXX_CONSTEXPR int_type
136 to_int_type(
const char_type& __c)
137 {
return static_cast<int_type
>(__c); }
139 static _GLIBCXX_CONSTEXPR
bool 140 eq_int_type(
const int_type& __c1,
const int_type& __c2)
141 {
return __c1 == __c2; }
143 static _GLIBCXX_CONSTEXPR int_type
145 {
return static_cast<int_type
>(_GLIBCXX_STDIO_EOF); }
147 static _GLIBCXX_CONSTEXPR int_type
148 not_eof(
const int_type& __c)
149 {
return !eq_int_type(__c, eof()) ? __c : to_int_type(char_type()); }
152 template<
typename _CharT>
153 _GLIBCXX14_CONSTEXPR
int 155 compare(
const char_type* __s1,
const char_type* __s2, std::size_t __n)
157 for (std::size_t __i = 0; __i < __n; ++__i)
158 if (lt(__s1[__i], __s2[__i]))
160 else if (lt(__s2[__i], __s1[__i]))
165 template<
typename _CharT>
166 _GLIBCXX14_CONSTEXPR std::size_t
167 char_traits<_CharT>::
168 length(
const char_type* __p)
171 while (!eq(__p[__i], char_type()))
176 template<
typename _CharT>
177 _GLIBCXX14_CONSTEXPR
const typename char_traits<_CharT>::char_type*
178 char_traits<_CharT>::
179 find(
const char_type* __s, std::size_t __n,
const char_type& __a)
181 for (std::size_t __i = 0; __i < __n; ++__i)
182 if (eq(__s[__i], __a))
187 template<
typename _CharT>
189 typename char_traits<_CharT>::char_type*
190 char_traits<_CharT>::
191 move(char_type* __s1,
const char_type* __s2, std::size_t __n)
195 #ifdef __cpp_lib_is_constant_evaluated 196 if (std::is_constant_evaluated())
198 if (__s1 > __s2 && __s1 < __s2 + __n)
201 std::copy(__s2, __s2 + __n, __s1);
205 return static_cast<_CharT*
>(__builtin_memmove(__s1, __s2,
206 __n *
sizeof(char_type)));
209 template<
typename _CharT>
211 typename char_traits<_CharT>::char_type*
212 char_traits<_CharT>::
213 copy(char_type* __s1,
const char_type* __s2, std::size_t __n)
216 std::copy(__s2, __s2 + __n, __s1);
220 template<
typename _CharT>
222 typename char_traits<_CharT>::char_type*
223 char_traits<_CharT>::
224 assign(char_type* __s, std::size_t __n, char_type __a)
231 _GLIBCXX_END_NAMESPACE_VERSION
234 namespace std _GLIBCXX_VISIBILITY(default)
236 _GLIBCXX_BEGIN_NAMESPACE_VERSION
238 #if __cplusplus >= 201703L 240 #ifdef __cpp_lib_is_constant_evaluated 242 # define __cpp_lib_constexpr_char_traits 201811L 245 # define __cpp_lib_constexpr_char_traits 201611L 255 template<
typename _CharT>
256 _GLIBCXX_ALWAYS_INLINE constexpr
bool 259 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED 262 return __builtin_is_constant_evaluated();
264 while (__builtin_constant_p(*__s) && *__s)
266 return __builtin_constant_p(*__s);
278 template<
typename _CharT>
279 _GLIBCXX_ALWAYS_INLINE constexpr
bool 282 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED 286 return __builtin_is_constant_evaluated();
289 while (__i < __n && __builtin_constant_p(__a[__i]))
309 template<
class _CharT>
318 typedef char char_type;
319 typedef int int_type;
322 typedef mbstate_t state_type;
323 #if __cpp_lib_three_way_comparison 324 using comparison_category = strong_ordering;
327 static _GLIBCXX17_CONSTEXPR
void 328 assign(char_type& __c1,
const char_type& __c2) _GLIBCXX_NOEXCEPT
331 static _GLIBCXX_CONSTEXPR
bool 332 eq(
const char_type& __c1,
const char_type& __c2) _GLIBCXX_NOEXCEPT
333 {
return __c1 == __c2; }
335 static _GLIBCXX_CONSTEXPR
bool 336 lt(
const char_type& __c1,
const char_type& __c2) _GLIBCXX_NOEXCEPT
339 return (static_cast<unsigned char>(__c1)
340 < static_cast<unsigned char>(__c2));
343 static _GLIBCXX17_CONSTEXPR
int 344 compare(
const char_type* __s1,
const char_type* __s2,
size_t __n)
348 #if __cplusplus >= 201703L 349 if (__builtin_constant_p(__n)
353 for (
size_t __i = 0; __i < __n; ++__i)
354 if (lt(__s1[__i], __s2[__i]))
356 else if (lt(__s2[__i], __s1[__i]))
361 return __builtin_memcmp(__s1, __s2, __n);
364 static _GLIBCXX17_CONSTEXPR
size_t 365 length(
const char_type* __s)
367 #if __cplusplus >= 201703L 371 return __builtin_strlen(__s);
374 static _GLIBCXX17_CONSTEXPR
const char_type*
375 find(
const char_type* __s,
size_t __n,
const char_type& __a)
379 #if __cplusplus >= 201703L 380 if (__builtin_constant_p(__n)
381 && __builtin_constant_p(__a)
385 return static_cast<const char_type*
>(__builtin_memchr(__s, __a, __n));
388 static _GLIBCXX20_CONSTEXPR char_type*
389 move(char_type* __s1,
const char_type* __s2,
size_t __n)
393 #ifdef __cpp_lib_is_constant_evaluated 394 if (std::is_constant_evaluated())
397 return static_cast<char_type*
>(__builtin_memmove(__s1, __s2, __n));
400 static _GLIBCXX20_CONSTEXPR char_type*
401 copy(char_type* __s1,
const char_type* __s2,
size_t __n)
405 #ifdef __cpp_lib_is_constant_evaluated 406 if (std::is_constant_evaluated())
409 return static_cast<char_type*
>(__builtin_memcpy(__s1, __s2, __n));
412 static _GLIBCXX20_CONSTEXPR char_type*
413 assign(char_type* __s,
size_t __n, char_type __a)
417 #ifdef __cpp_lib_is_constant_evaluated 418 if (std::is_constant_evaluated())
421 return static_cast<char_type*
>(__builtin_memset(__s, __a, __n));
424 static _GLIBCXX_CONSTEXPR char_type
425 to_char_type(
const int_type& __c) _GLIBCXX_NOEXCEPT
426 {
return static_cast<char_type
>(__c); }
430 static _GLIBCXX_CONSTEXPR int_type
431 to_int_type(
const char_type& __c) _GLIBCXX_NOEXCEPT
432 {
return static_cast<int_type
>(
static_cast<unsigned char>(__c)); }
434 static _GLIBCXX_CONSTEXPR
bool 435 eq_int_type(
const int_type& __c1,
const int_type& __c2) _GLIBCXX_NOEXCEPT
436 {
return __c1 == __c2; }
438 static _GLIBCXX_CONSTEXPR int_type
439 eof() _GLIBCXX_NOEXCEPT
440 {
return static_cast<int_type
>(_GLIBCXX_STDIO_EOF); }
442 static _GLIBCXX_CONSTEXPR int_type
443 not_eof(
const int_type& __c) _GLIBCXX_NOEXCEPT
444 {
return (__c == eof()) ? 0 : __c; }
448 #ifdef _GLIBCXX_USE_WCHAR_T 453 typedef wchar_t char_type;
454 typedef wint_t int_type;
457 typedef mbstate_t state_type;
458 #if __cpp_lib_three_way_comparison 459 using comparison_category = strong_ordering;
462 static _GLIBCXX17_CONSTEXPR
void 463 assign(char_type& __c1,
const char_type& __c2) _GLIBCXX_NOEXCEPT
466 static _GLIBCXX_CONSTEXPR
bool 467 eq(
const char_type& __c1,
const char_type& __c2) _GLIBCXX_NOEXCEPT
468 {
return __c1 == __c2; }
470 static _GLIBCXX_CONSTEXPR
bool 471 lt(
const char_type& __c1,
const char_type& __c2) _GLIBCXX_NOEXCEPT
472 {
return __c1 < __c2; }
474 static _GLIBCXX17_CONSTEXPR
int 475 compare(
const char_type* __s1,
const char_type* __s2,
size_t __n)
479 #if __cplusplus >= 201703L 480 if (__builtin_constant_p(__n)
485 return wmemcmp(__s1, __s2, __n);
488 static _GLIBCXX17_CONSTEXPR
size_t 489 length(
const char_type* __s)
491 #if __cplusplus >= 201703L 498 static _GLIBCXX17_CONSTEXPR
const char_type*
499 find(
const char_type* __s,
size_t __n,
const char_type& __a)
503 #if __cplusplus >= 201703L 504 if (__builtin_constant_p(__n)
505 && __builtin_constant_p(__a)
509 return wmemchr(__s, __a, __n);
512 static _GLIBCXX20_CONSTEXPR char_type*
513 move(char_type* __s1,
const char_type* __s2,
size_t __n)
517 #ifdef __cpp_lib_is_constant_evaluated 518 if (std::is_constant_evaluated())
521 return wmemmove(__s1, __s2, __n);
524 static _GLIBCXX20_CONSTEXPR char_type*
525 copy(char_type* __s1,
const char_type* __s2,
size_t __n)
529 #ifdef __cpp_lib_is_constant_evaluated 530 if (std::is_constant_evaluated())
533 return wmemcpy(__s1, __s2, __n);
536 static _GLIBCXX20_CONSTEXPR char_type*
537 assign(char_type* __s,
size_t __n, char_type __a)
541 #ifdef __cpp_lib_is_constant_evaluated 542 if (std::is_constant_evaluated())
545 return wmemset(__s, __a, __n);
548 static _GLIBCXX_CONSTEXPR char_type
549 to_char_type(
const int_type& __c) _GLIBCXX_NOEXCEPT
550 {
return char_type(__c); }
552 static _GLIBCXX_CONSTEXPR int_type
553 to_int_type(
const char_type& __c) _GLIBCXX_NOEXCEPT
554 {
return int_type(__c); }
556 static _GLIBCXX_CONSTEXPR
bool 557 eq_int_type(
const int_type& __c1,
const int_type& __c2) _GLIBCXX_NOEXCEPT
558 {
return __c1 == __c2; }
560 static _GLIBCXX_CONSTEXPR int_type
561 eof() _GLIBCXX_NOEXCEPT
562 {
return static_cast<int_type
>(WEOF); }
564 static _GLIBCXX_CONSTEXPR int_type
565 not_eof(
const int_type& __c) _GLIBCXX_NOEXCEPT
566 {
return eq_int_type(__c, eof()) ? 0 : __c; }
568 #endif //_GLIBCXX_USE_WCHAR_T 570 #ifdef _GLIBCXX_USE_CHAR8_T 574 typedef char8_t char_type;
575 typedef unsigned int int_type;
576 typedef u8streampos pos_type;
578 typedef mbstate_t state_type;
579 #if __cpp_lib_three_way_comparison 580 using comparison_category = strong_ordering;
583 static _GLIBCXX17_CONSTEXPR
void 584 assign(char_type& __c1,
const char_type& __c2) _GLIBCXX_NOEXCEPT
587 static _GLIBCXX_CONSTEXPR
bool 588 eq(
const char_type& __c1,
const char_type& __c2) _GLIBCXX_NOEXCEPT
589 {
return __c1 == __c2; }
591 static _GLIBCXX_CONSTEXPR
bool 592 lt(
const char_type& __c1,
const char_type& __c2) _GLIBCXX_NOEXCEPT
593 {
return __c1 < __c2; }
595 static _GLIBCXX17_CONSTEXPR
int 596 compare(
const char_type* __s1,
const char_type* __s2,
size_t __n)
600 #if __cplusplus > 201402 601 if (__builtin_constant_p(__n)
606 return __builtin_memcmp(__s1, __s2, __n);
609 static _GLIBCXX17_CONSTEXPR
size_t 610 length(
const char_type* __s)
612 #if __cplusplus > 201402 617 while (!eq(__s[__i], char_type()))
622 static _GLIBCXX17_CONSTEXPR
const char_type*
623 find(
const char_type* __s,
size_t __n,
const char_type& __a)
627 #if __cplusplus > 201402 628 if (__builtin_constant_p(__n)
629 && __builtin_constant_p(__a)
633 return static_cast<const char_type*
>(__builtin_memchr(__s, __a, __n));
636 static _GLIBCXX20_CONSTEXPR char_type*
637 move(char_type* __s1,
const char_type* __s2,
size_t __n)
641 #ifdef __cpp_lib_is_constant_evaluated 642 if (std::is_constant_evaluated())
645 return static_cast<char_type*
>(__builtin_memmove(__s1, __s2, __n));
648 static _GLIBCXX20_CONSTEXPR char_type*
649 copy(char_type* __s1,
const char_type* __s2,
size_t __n)
653 #ifdef __cpp_lib_is_constant_evaluated 654 if (std::is_constant_evaluated())
657 return static_cast<char_type*
>(__builtin_memcpy(__s1, __s2, __n));
660 static _GLIBCXX20_CONSTEXPR char_type*
661 assign(char_type* __s,
size_t __n, char_type __a)
665 #ifdef __cpp_lib_is_constant_evaluated 666 if (std::is_constant_evaluated())
669 return static_cast<char_type*
>(__builtin_memset(__s, __a, __n));
672 static _GLIBCXX_CONSTEXPR char_type
673 to_char_type(
const int_type& __c) _GLIBCXX_NOEXCEPT
674 {
return char_type(__c); }
676 static _GLIBCXX_CONSTEXPR int_type
677 to_int_type(
const char_type& __c) _GLIBCXX_NOEXCEPT
678 {
return int_type(__c); }
680 static _GLIBCXX_CONSTEXPR
bool 681 eq_int_type(
const int_type& __c1,
const int_type& __c2) _GLIBCXX_NOEXCEPT
682 {
return __c1 == __c2; }
684 static _GLIBCXX_CONSTEXPR int_type
685 eof() _GLIBCXX_NOEXCEPT
686 {
return static_cast<int_type
>(-1); }
688 static _GLIBCXX_CONSTEXPR int_type
689 not_eof(
const int_type& __c) _GLIBCXX_NOEXCEPT
690 {
return eq_int_type(__c, eof()) ? 0 : __c; }
692 #endif //_GLIBCXX_USE_CHAR8_T 694 _GLIBCXX_END_NAMESPACE_VERSION
697 #if __cplusplus >= 201103L 701 namespace std _GLIBCXX_VISIBILITY(default)
703 _GLIBCXX_BEGIN_NAMESPACE_VERSION
706 struct char_traits<char16_t>
708 typedef char16_t char_type;
709 #ifdef _GLIBCXX_USE_C99_STDINT_TR1 710 typedef uint_least16_t int_type;
711 #elif defined __UINT_LEAST16_TYPE__ 712 typedef __UINT_LEAST16_TYPE__ int_type;
714 typedef make_unsigned<char16_t>::type int_type;
718 typedef mbstate_t state_type;
719 #if __cpp_lib_three_way_comparison 720 using comparison_category = strong_ordering;
723 static _GLIBCXX17_CONSTEXPR
void 724 assign(char_type& __c1,
const char_type& __c2) noexcept
727 static constexpr
bool 728 eq(
const char_type& __c1,
const char_type& __c2) noexcept
729 {
return __c1 == __c2; }
731 static constexpr
bool 732 lt(
const char_type& __c1,
const char_type& __c2) noexcept
733 {
return __c1 < __c2; }
735 static _GLIBCXX17_CONSTEXPR
int 736 compare(
const char_type* __s1,
const char_type* __s2,
size_t __n)
738 for (
size_t __i = 0; __i < __n; ++__i)
739 if (lt(__s1[__i], __s2[__i]))
741 else if (lt(__s2[__i], __s1[__i]))
746 static _GLIBCXX17_CONSTEXPR
size_t 747 length(
const char_type* __s)
750 while (!eq(__s[__i], char_type()))
755 static _GLIBCXX17_CONSTEXPR
const char_type*
756 find(
const char_type* __s,
size_t __n,
const char_type& __a)
758 for (
size_t __i = 0; __i < __n; ++__i)
759 if (eq(__s[__i], __a))
764 static _GLIBCXX20_CONSTEXPR char_type*
765 move(char_type* __s1,
const char_type* __s2,
size_t __n)
769 #ifdef __cpp_lib_is_constant_evaluated 770 if (std::is_constant_evaluated())
773 return (static_cast<char_type*>
774 (__builtin_memmove(__s1, __s2, __n *
sizeof(char_type))));
777 static _GLIBCXX20_CONSTEXPR char_type*
778 copy(char_type* __s1,
const char_type* __s2,
size_t __n)
782 #ifdef __cpp_lib_is_constant_evaluated 783 if (std::is_constant_evaluated())
786 return (static_cast<char_type*>
787 (__builtin_memcpy(__s1, __s2, __n *
sizeof(char_type))));
790 static _GLIBCXX20_CONSTEXPR char_type*
791 assign(char_type* __s,
size_t __n, char_type __a)
793 for (
size_t __i = 0; __i < __n; ++__i)
794 assign(__s[__i], __a);
798 static constexpr char_type
799 to_char_type(
const int_type& __c) noexcept
800 {
return char_type(__c); }
802 static constexpr int_type
803 to_int_type(
const char_type& __c) noexcept
804 {
return __c == eof() ? int_type(0xfffd) : int_type(__c); }
806 static constexpr
bool 807 eq_int_type(
const int_type& __c1,
const int_type& __c2) noexcept
808 {
return __c1 == __c2; }
810 static constexpr int_type
812 {
return static_cast<int_type
>(-1); }
814 static constexpr int_type
815 not_eof(
const int_type& __c) noexcept
816 {
return eq_int_type(__c, eof()) ? 0 : __c; }
820 struct char_traits<char32_t>
822 typedef char32_t char_type;
823 #ifdef _GLIBCXX_USE_C99_STDINT_TR1 824 typedef uint_least32_t int_type;
825 #elif defined __UINT_LEAST32_TYPE__ 826 typedef __UINT_LEAST32_TYPE__ int_type;
828 typedef make_unsigned<char32_t>::type int_type;
832 typedef mbstate_t state_type;
833 #if __cpp_lib_three_way_comparison 834 using comparison_category = strong_ordering;
837 static _GLIBCXX17_CONSTEXPR
void 838 assign(char_type& __c1,
const char_type& __c2) noexcept
841 static constexpr
bool 842 eq(
const char_type& __c1,
const char_type& __c2) noexcept
843 {
return __c1 == __c2; }
845 static constexpr
bool 846 lt(
const char_type& __c1,
const char_type& __c2) noexcept
847 {
return __c1 < __c2; }
849 static _GLIBCXX17_CONSTEXPR
int 850 compare(
const char_type* __s1,
const char_type* __s2,
size_t __n)
852 for (
size_t __i = 0; __i < __n; ++__i)
853 if (lt(__s1[__i], __s2[__i]))
855 else if (lt(__s2[__i], __s1[__i]))
860 static _GLIBCXX17_CONSTEXPR
size_t 861 length(
const char_type* __s)
864 while (!eq(__s[__i], char_type()))
869 static _GLIBCXX17_CONSTEXPR
const char_type*
870 find(
const char_type* __s,
size_t __n,
const char_type& __a)
872 for (
size_t __i = 0; __i < __n; ++__i)
873 if (eq(__s[__i], __a))
878 static _GLIBCXX20_CONSTEXPR char_type*
879 move(char_type* __s1,
const char_type* __s2,
size_t __n)
883 #ifdef __cpp_lib_is_constant_evaluated 884 if (std::is_constant_evaluated())
887 return (static_cast<char_type*>
888 (__builtin_memmove(__s1, __s2, __n *
sizeof(char_type))));
891 static _GLIBCXX20_CONSTEXPR char_type*
892 copy(char_type* __s1,
const char_type* __s2,
size_t __n)
896 #ifdef __cpp_lib_is_constant_evaluated 897 if (std::is_constant_evaluated())
900 return (static_cast<char_type*>
901 (__builtin_memcpy(__s1, __s2, __n *
sizeof(char_type))));
904 static _GLIBCXX20_CONSTEXPR char_type*
905 assign(char_type* __s,
size_t __n, char_type __a)
907 for (
size_t __i = 0; __i < __n; ++__i)
908 assign(__s[__i], __a);
912 static constexpr char_type
913 to_char_type(
const int_type& __c) noexcept
914 {
return char_type(__c); }
916 static constexpr int_type
917 to_int_type(
const char_type& __c) noexcept
918 {
return int_type(__c); }
920 static constexpr
bool 921 eq_int_type(
const int_type& __c1,
const int_type& __c2) noexcept
922 {
return __c1 == __c2; }
924 static constexpr int_type
926 {
return static_cast<int_type
>(-1); }
928 static constexpr int_type
929 not_eof(
const int_type& __c) noexcept
930 {
return eq_int_type(__c, eof()) ? 0 : __c; }
933 #if __cpp_lib_three_way_comparison 936 template<
typename _ChTraits>
938 __char_traits_cmp_cat(
int __cmp) noexcept
940 if constexpr (requires {
typename _ChTraits::comparison_category; })
942 using _Cat =
typename _ChTraits::comparison_category;
943 static_assert( !is_void_v<common_comparison_category_t<_Cat>> );
944 return static_cast<_Cat
>(__cmp <=> 0);
947 return static_cast<weak_ordering
>(__cmp <=> 0);
952 _GLIBCXX_END_NAMESPACE_VERSION
957 #endif // _CHAR_TRAITS_H
constexpr bool __constant_char_array_p(const _CharT *__a, size_t __n)
Determine whether the characters of a character array are known at compile time.
Mapping from character type to associated types.
constexpr _BI2 copy_backward(_BI1 __first, _BI1 __last, _BI2 __result)
Copies the range [first,last) into result.
ISO C++ entities toplevel namespace is std.
Basis for explicit traits specializations.
constexpr _OI fill_n(_OI __first, _Size __n, const _Tp &__value)
Fills the range [first,first+n) with copies of value.
GNU extensions for public use.
Base class used to implement std::char_traits.
long long streamoff
Type used by fpos, char_traits<char>, and char_traits<wchar_t>.
constexpr bool __constant_string_p(const _CharT *__s)
Determine whether the characters of a NULL-terminated string are known at compile time...
fpos< mbstate_t > u32streampos
File position for char32_t streams.
fpos< mbstate_t > u16streampos
File position for char16_t streams.
Class representing stream positions.