1 // C++11 <type_traits> -*- C++ -*-
3 // Copyright (C) 2007-2016 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 include/type_traits
26 * This is a Standard C++ Library header.
29 #ifndef _GLIBCXX_TYPE_TRAITS
30 #define _GLIBCXX_TYPE_TRAITS 1
32 #pragma GCC system_header
34 #if __cplusplus < 201103L
35 # include <bits/c++0x_warning.h>
38 #include <bits/c++config.h>
40 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
41 # if defined (__UINT_LEAST16_TYPE__) && defined(__UINT_LEAST32_TYPE__)
44 typedef __UINT_LEAST16_TYPE__ uint_least16_t;
45 typedef __UINT_LEAST32_TYPE__ uint_least32_t;
52 namespace std _GLIBCXX_VISIBILITY(default)
54 _GLIBCXX_BEGIN_NAMESPACE_VERSION
57 * @defgroup metaprogramming Metaprogramming
60 * Template utilities for compile-time introspection and modification,
61 * including type classification traits, type property inspection traits
62 * and type transformation traits.
68 template<typename _Tp, _Tp __v>
69 struct integral_constant
71 static constexpr _Tp value = __v;
72 typedef _Tp value_type;
73 typedef integral_constant<_Tp, __v> type;
74 constexpr operator value_type() const { return value; }
75 #if __cplusplus > 201103L
77 #define __cpp_lib_integral_constant_callable 201304
79 constexpr value_type operator()() const { return value; }
83 template<typename _Tp, _Tp __v>
84 constexpr _Tp integral_constant<_Tp, __v>::value;
86 /// The type used as a compile-time boolean with true value.
87 typedef integral_constant<bool, true> true_type;
89 /// The type used as a compile-time boolean with false value.
90 typedef integral_constant<bool, false> false_type;
93 using __bool_constant = integral_constant<bool, __v>;
95 #if __cplusplus > 201402L
96 # define __cpp_lib_bool_constant 201505
98 using bool_constant = integral_constant<bool, __v>;
101 // Meta programming helper types.
103 template<bool, typename, typename>
106 template<typename...>
114 template<typename _B1>
119 template<typename _B1, typename _B2>
120 struct __or_<_B1, _B2>
121 : public conditional<_B1::value, _B1, _B2>::type
124 template<typename _B1, typename _B2, typename _B3, typename... _Bn>
125 struct __or_<_B1, _B2, _B3, _Bn...>
126 : public conditional<_B1::value, _B1, __or_<_B2, _B3, _Bn...>>::type
129 template<typename...>
137 template<typename _B1>
142 template<typename _B1, typename _B2>
143 struct __and_<_B1, _B2>
144 : public conditional<_B1::value, _B2, _B1>::type
147 template<typename _B1, typename _B2, typename _B3, typename... _Bn>
148 struct __and_<_B1, _B2, _B3, _Bn...>
149 : public conditional<_B1::value, __and_<_B2, _B3, _Bn...>, _B1>::type
152 template<typename _Pp>
154 : public integral_constant<bool, !_Pp::value>
157 #if __cplusplus > 201402L
159 #define __cpp_lib_logical_traits 201510
161 template<typename... _Bn>
166 template<typename... _Bn>
171 template<typename _Pp>
177 // For several sfinae-friendly trait implementations we transport both the
178 // result information (as the member type) and the failure information (no
179 // member type). This is very similar to std::enable_if, but we cannot use
180 // them, because we need to derive from them as an implementation detail.
182 template<typename _Tp>
183 struct __success_type
184 { typedef _Tp type; };
186 struct __failure_type
189 // Primary type categories.
195 struct __is_void_helper
196 : public false_type { };
199 struct __is_void_helper<void>
200 : public true_type { };
203 template<typename _Tp>
205 : public __is_void_helper<typename remove_cv<_Tp>::type>::type
209 struct __is_integral_helper
210 : public false_type { };
213 struct __is_integral_helper<bool>
214 : public true_type { };
217 struct __is_integral_helper<char>
218 : public true_type { };
221 struct __is_integral_helper<signed char>
222 : public true_type { };
225 struct __is_integral_helper<unsigned char>
226 : public true_type { };
228 #ifdef _GLIBCXX_USE_WCHAR_T
230 struct __is_integral_helper<wchar_t>
231 : public true_type { };
235 struct __is_integral_helper<char16_t>
236 : public true_type { };
239 struct __is_integral_helper<char32_t>
240 : public true_type { };
243 struct __is_integral_helper<short>
244 : public true_type { };
247 struct __is_integral_helper<unsigned short>
248 : public true_type { };
251 struct __is_integral_helper<int>
252 : public true_type { };
255 struct __is_integral_helper<unsigned int>
256 : public true_type { };
259 struct __is_integral_helper<long>
260 : public true_type { };
263 struct __is_integral_helper<unsigned long>
264 : public true_type { };
267 struct __is_integral_helper<long long>
268 : public true_type { };
271 struct __is_integral_helper<unsigned long long>
272 : public true_type { };
274 // Conditionalizing on __STRICT_ANSI__ here will break any port that
275 // uses one of these types for size_t.
276 #if defined(__GLIBCXX_TYPE_INT_N_0)
278 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_0>
279 : public true_type { };
282 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_0>
283 : public true_type { };
285 #if defined(__GLIBCXX_TYPE_INT_N_1)
287 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_1>
288 : public true_type { };
291 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_1>
292 : public true_type { };
294 #if defined(__GLIBCXX_TYPE_INT_N_2)
296 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_2>
297 : public true_type { };
300 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_2>
301 : public true_type { };
303 #if defined(__GLIBCXX_TYPE_INT_N_3)
305 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_3>
306 : public true_type { };
309 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_3>
310 : public true_type { };
314 template<typename _Tp>
316 : public __is_integral_helper<typename remove_cv<_Tp>::type>::type
320 struct __is_floating_point_helper
321 : public false_type { };
324 struct __is_floating_point_helper<float>
325 : public true_type { };
328 struct __is_floating_point_helper<double>
329 : public true_type { };
332 struct __is_floating_point_helper<long double>
333 : public true_type { };
335 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
337 struct __is_floating_point_helper<__float128>
338 : public true_type { };
341 /// is_floating_point
342 template<typename _Tp>
343 struct is_floating_point
344 : public __is_floating_point_helper<typename remove_cv<_Tp>::type>::type
350 : public false_type { };
352 template<typename _Tp, std::size_t _Size>
353 struct is_array<_Tp[_Size]>
354 : public true_type { };
356 template<typename _Tp>
357 struct is_array<_Tp[]>
358 : public true_type { };
361 struct __is_pointer_helper
362 : public false_type { };
364 template<typename _Tp>
365 struct __is_pointer_helper<_Tp*>
366 : public true_type { };
369 template<typename _Tp>
371 : public __is_pointer_helper<typename remove_cv<_Tp>::type>::type
374 /// is_lvalue_reference
376 struct is_lvalue_reference
377 : public false_type { };
379 template<typename _Tp>
380 struct is_lvalue_reference<_Tp&>
381 : public true_type { };
383 /// is_rvalue_reference
385 struct is_rvalue_reference
386 : public false_type { };
388 template<typename _Tp>
389 struct is_rvalue_reference<_Tp&&>
390 : public true_type { };
396 struct __is_member_object_pointer_helper
397 : public false_type { };
399 template<typename _Tp, typename _Cp>
400 struct __is_member_object_pointer_helper<_Tp _Cp::*>
401 : public integral_constant<bool, !is_function<_Tp>::value> { };
403 /// is_member_object_pointer
404 template<typename _Tp>
405 struct is_member_object_pointer
406 : public __is_member_object_pointer_helper<
407 typename remove_cv<_Tp>::type>::type
411 struct __is_member_function_pointer_helper
412 : public false_type { };
414 template<typename _Tp, typename _Cp>
415 struct __is_member_function_pointer_helper<_Tp _Cp::*>
416 : public integral_constant<bool, is_function<_Tp>::value> { };
418 /// is_member_function_pointer
419 template<typename _Tp>
420 struct is_member_function_pointer
421 : public __is_member_function_pointer_helper<
422 typename remove_cv<_Tp>::type>::type
426 template<typename _Tp>
428 : public integral_constant<bool, __is_enum(_Tp)>
432 template<typename _Tp>
434 : public integral_constant<bool, __is_union(_Tp)>
438 template<typename _Tp>
440 : public integral_constant<bool, __is_class(_Tp)>
446 : public false_type { };
448 template<typename _Res, typename... _ArgTypes>
449 struct is_function<_Res(_ArgTypes...)>
450 : public true_type { };
452 template<typename _Res, typename... _ArgTypes>
453 struct is_function<_Res(_ArgTypes...) &>
454 : public true_type { };
456 template<typename _Res, typename... _ArgTypes>
457 struct is_function<_Res(_ArgTypes...) &&>
458 : public true_type { };
460 template<typename _Res, typename... _ArgTypes>
461 struct is_function<_Res(_ArgTypes......)>
462 : public true_type { };
464 template<typename _Res, typename... _ArgTypes>
465 struct is_function<_Res(_ArgTypes......) &>
466 : public true_type { };
468 template<typename _Res, typename... _ArgTypes>
469 struct is_function<_Res(_ArgTypes......) &&>
470 : public true_type { };
472 template<typename _Res, typename... _ArgTypes>
473 struct is_function<_Res(_ArgTypes...) const>
474 : public true_type { };
476 template<typename _Res, typename... _ArgTypes>
477 struct is_function<_Res(_ArgTypes...) const &>
478 : public true_type { };
480 template<typename _Res, typename... _ArgTypes>
481 struct is_function<_Res(_ArgTypes...) const &&>
482 : public true_type { };
484 template<typename _Res, typename... _ArgTypes>
485 struct is_function<_Res(_ArgTypes......) const>
486 : public true_type { };
488 template<typename _Res, typename... _ArgTypes>
489 struct is_function<_Res(_ArgTypes......) const &>
490 : public true_type { };
492 template<typename _Res, typename... _ArgTypes>
493 struct is_function<_Res(_ArgTypes......) const &&>
494 : public true_type { };
496 template<typename _Res, typename... _ArgTypes>
497 struct is_function<_Res(_ArgTypes...) volatile>
498 : public true_type { };
500 template<typename _Res, typename... _ArgTypes>
501 struct is_function<_Res(_ArgTypes...) volatile &>
502 : public true_type { };
504 template<typename _Res, typename... _ArgTypes>
505 struct is_function<_Res(_ArgTypes...) volatile &&>
506 : public true_type { };
508 template<typename _Res, typename... _ArgTypes>
509 struct is_function<_Res(_ArgTypes......) volatile>
510 : public true_type { };
512 template<typename _Res, typename... _ArgTypes>
513 struct is_function<_Res(_ArgTypes......) volatile &>
514 : public true_type { };
516 template<typename _Res, typename... _ArgTypes>
517 struct is_function<_Res(_ArgTypes......) volatile &&>
518 : public true_type { };
520 template<typename _Res, typename... _ArgTypes>
521 struct is_function<_Res(_ArgTypes...) const volatile>
522 : public true_type { };
524 template<typename _Res, typename... _ArgTypes>
525 struct is_function<_Res(_ArgTypes...) const volatile &>
526 : public true_type { };
528 template<typename _Res, typename... _ArgTypes>
529 struct is_function<_Res(_ArgTypes...) const volatile &&>
530 : public true_type { };
532 template<typename _Res, typename... _ArgTypes>
533 struct is_function<_Res(_ArgTypes......) const volatile>
534 : public true_type { };
536 template<typename _Res, typename... _ArgTypes>
537 struct is_function<_Res(_ArgTypes......) const volatile &>
538 : public true_type { };
540 template<typename _Res, typename... _ArgTypes>
541 struct is_function<_Res(_ArgTypes......) const volatile &&>
542 : public true_type { };
544 #define __cpp_lib_is_null_pointer 201309
547 struct __is_null_pointer_helper
548 : public false_type { };
551 struct __is_null_pointer_helper<std::nullptr_t>
552 : public true_type { };
554 /// is_null_pointer (LWG 2247).
555 template<typename _Tp>
556 struct is_null_pointer
557 : public __is_null_pointer_helper<typename remove_cv<_Tp>::type>::type
560 /// __is_nullptr_t (extension).
561 template<typename _Tp>
562 struct __is_nullptr_t
563 : public is_null_pointer<_Tp>
566 // Composite type categories.
569 template<typename _Tp>
571 : public __or_<is_lvalue_reference<_Tp>,
572 is_rvalue_reference<_Tp>>::type
576 template<typename _Tp>
578 : public __or_<is_integral<_Tp>, is_floating_point<_Tp>>::type
582 template<typename _Tp>
583 struct is_fundamental
584 : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
585 is_null_pointer<_Tp>>::type
589 template<typename _Tp>
591 : public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
596 struct is_member_pointer;
599 template<typename _Tp>
601 : public __or_<is_arithmetic<_Tp>, is_enum<_Tp>, is_pointer<_Tp>,
602 is_member_pointer<_Tp>, is_null_pointer<_Tp>>::type
606 template<typename _Tp>
608 : public integral_constant<bool, !is_fundamental<_Tp>::value> { };
610 template<typename _Tp>
611 struct __is_member_pointer_helper
612 : public false_type { };
614 template<typename _Tp, typename _Cp>
615 struct __is_member_pointer_helper<_Tp _Cp::*>
616 : public true_type { };
618 /// is_member_pointer
619 template<typename _Tp>
620 struct is_member_pointer
621 : public __is_member_pointer_helper<typename remove_cv<_Tp>::type>::type
624 // Utility to detect referenceable types ([defns.referenceable]).
626 template<typename _Tp>
627 struct __is_referenceable
628 : public __or_<is_object<_Tp>, is_reference<_Tp>>::type
631 template<typename _Res, typename... _Args>
632 struct __is_referenceable<_Res(_Args...)>
636 template<typename _Res, typename... _Args>
637 struct __is_referenceable<_Res(_Args......)>
646 : public false_type { };
648 template<typename _Tp>
649 struct is_const<_Tp const>
650 : public true_type { };
655 : public false_type { };
657 template<typename _Tp>
658 struct is_volatile<_Tp volatile>
659 : public true_type { };
662 template<typename _Tp>
664 : public integral_constant<bool, __is_trivial(_Tp)>
667 // is_trivially_copyable
668 template<typename _Tp>
669 struct is_trivially_copyable
670 : public integral_constant<bool, __is_trivially_copyable(_Tp)>
673 /// is_standard_layout
674 template<typename _Tp>
675 struct is_standard_layout
676 : public integral_constant<bool, __is_standard_layout(_Tp)>
680 // Could use is_standard_layout && is_trivial instead of the builtin.
681 template<typename _Tp>
683 : public integral_constant<bool, __is_pod(_Tp)>
687 template<typename _Tp>
688 struct is_literal_type
689 : public integral_constant<bool, __is_literal_type(_Tp)>
693 template<typename _Tp>
695 : public integral_constant<bool, __is_empty(_Tp)>
699 template<typename _Tp>
700 struct is_polymorphic
701 : public integral_constant<bool, __is_polymorphic(_Tp)>
704 #if __cplusplus >= 201402L
705 #define __cpp_lib_is_final 201402L
707 template<typename _Tp>
709 : public integral_constant<bool, __is_final(_Tp)>
714 template<typename _Tp>
716 : public integral_constant<bool, __is_abstract(_Tp)>
719 template<typename _Tp,
720 bool = is_arithmetic<_Tp>::value>
721 struct __is_signed_helper
722 : public false_type { };
724 template<typename _Tp>
725 struct __is_signed_helper<_Tp, true>
726 : public integral_constant<bool, _Tp(-1) < _Tp(0)>
730 template<typename _Tp>
732 : public __is_signed_helper<_Tp>::type
736 template<typename _Tp>
738 : public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>
742 // Destructible and constructible type properties.
745 struct add_rvalue_reference;
748 * @brief Utility to simplify expressions used in unevaluated operands
751 template<typename _Tp>
752 typename add_rvalue_reference<_Tp>::type declval() noexcept;
754 template<typename, unsigned = 0>
758 struct remove_all_extents;
760 template<typename _Tp>
761 struct __is_array_known_bounds
762 : public integral_constant<bool, (extent<_Tp>::value > 0)>
765 template<typename _Tp>
766 struct __is_array_unknown_bounds
767 : public __and_<is_array<_Tp>, __not_<extent<_Tp>>>
770 // In N3290 is_destructible does not say anything about function
771 // types and abstract types, see LWG 2049. This implementation
772 // describes function types as non-destructible and all complete
773 // object types as destructible, iff the explicit destructor
774 // call expression is wellformed.
775 struct __do_is_destructible_impl
777 template<typename _Tp, typename = decltype(declval<_Tp&>().~_Tp())>
778 static true_type __test(int);
781 static false_type __test(...);
784 template<typename _Tp>
785 struct __is_destructible_impl
786 : public __do_is_destructible_impl
788 typedef decltype(__test<_Tp>(0)) type;
791 template<typename _Tp,
792 bool = __or_<is_void<_Tp>,
793 __is_array_unknown_bounds<_Tp>,
794 is_function<_Tp>>::value,
795 bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
796 struct __is_destructible_safe;
798 template<typename _Tp>
799 struct __is_destructible_safe<_Tp, false, false>
800 : public __is_destructible_impl<typename
801 remove_all_extents<_Tp>::type>::type
804 template<typename _Tp>
805 struct __is_destructible_safe<_Tp, true, false>
806 : public false_type { };
808 template<typename _Tp>
809 struct __is_destructible_safe<_Tp, false, true>
810 : public true_type { };
813 template<typename _Tp>
814 struct is_destructible
815 : public __is_destructible_safe<_Tp>::type
818 // is_nothrow_destructible requires that is_destructible is
819 // satisfied as well. We realize that by mimicing the
820 // implementation of is_destructible but refer to noexcept(expr)
821 // instead of decltype(expr).
822 struct __do_is_nt_destructible_impl
824 template<typename _Tp>
825 static integral_constant<bool, noexcept(declval<_Tp&>().~_Tp())>
829 static false_type __test(...);
832 template<typename _Tp>
833 struct __is_nt_destructible_impl
834 : public __do_is_nt_destructible_impl
836 typedef decltype(__test<_Tp>(0)) type;
839 template<typename _Tp,
840 bool = __or_<is_void<_Tp>,
841 __is_array_unknown_bounds<_Tp>,
842 is_function<_Tp>>::value,
843 bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
844 struct __is_nt_destructible_safe;
846 template<typename _Tp>
847 struct __is_nt_destructible_safe<_Tp, false, false>
848 : public __is_nt_destructible_impl<typename
849 remove_all_extents<_Tp>::type>::type
852 template<typename _Tp>
853 struct __is_nt_destructible_safe<_Tp, true, false>
854 : public false_type { };
856 template<typename _Tp>
857 struct __is_nt_destructible_safe<_Tp, false, true>
858 : public true_type { };
860 /// is_nothrow_destructible
861 template<typename _Tp>
862 struct is_nothrow_destructible
863 : public __is_nt_destructible_safe<_Tp>::type
866 struct __do_is_default_constructible_impl
868 template<typename _Tp, typename = decltype(_Tp())>
869 static true_type __test(int);
872 static false_type __test(...);
875 template<typename _Tp>
876 struct __is_default_constructible_impl
877 : public __do_is_default_constructible_impl
879 typedef decltype(__test<_Tp>(0)) type;
882 template<typename _Tp>
883 struct __is_default_constructible_atom
884 : public __and_<__not_<is_void<_Tp>>,
885 __is_default_constructible_impl<_Tp>>
888 template<typename _Tp, bool = is_array<_Tp>::value>
889 struct __is_default_constructible_safe;
891 // The following technique is a workaround for a current core language
892 // restriction, which does not allow for array types to occur in
893 // functional casts of the form T(). Complete arrays can be default-
894 // constructed, if the element type is default-constructible, but
895 // arrays with unknown bounds are not.
896 template<typename _Tp>
897 struct __is_default_constructible_safe<_Tp, true>
898 : public __and_<__is_array_known_bounds<_Tp>,
899 __is_default_constructible_atom<typename
900 remove_all_extents<_Tp>::type>>
903 template<typename _Tp>
904 struct __is_default_constructible_safe<_Tp, false>
905 : public __is_default_constructible_atom<_Tp>::type
908 /// is_default_constructible
909 template<typename _Tp>
910 struct is_default_constructible
911 : public __is_default_constructible_safe<_Tp>::type
915 // Implementation of is_constructible.
917 // The hardest part of this trait is the binary direct-initialization
918 // case, because we hit into a functional cast of the form T(arg).
919 // This implementation uses different strategies depending on the
920 // target type to reduce the test overhead as much as possible:
922 // a) For a reference target type, we use a static_cast expression
923 // modulo its extra cases.
925 // b) For a non-reference target type we use a ::new expression.
926 struct __do_is_static_castable_impl
928 template<typename _From, typename _To, typename
929 = decltype(static_cast<_To>(declval<_From>()))>
930 static true_type __test(int);
932 template<typename, typename>
933 static false_type __test(...);
936 template<typename _From, typename _To>
937 struct __is_static_castable_impl
938 : public __do_is_static_castable_impl
940 typedef decltype(__test<_From, _To>(0)) type;
943 template<typename _From, typename _To>
944 struct __is_static_castable_safe
945 : public __is_static_castable_impl<_From, _To>::type
948 // __is_static_castable
949 template<typename _From, typename _To>
950 struct __is_static_castable
951 : public integral_constant<bool, (__is_static_castable_safe<
955 // Implementation for non-reference types. To meet the proper
956 // variable definition semantics, we also need to test for
957 // is_destructible in this case.
958 // This form should be simplified by a single expression:
959 // ::delete ::new _Tp(declval<_Arg>()), see c++/51222.
960 struct __do_is_direct_constructible_impl
962 template<typename _Tp, typename _Arg, typename
963 = decltype(::new _Tp(declval<_Arg>()))>
964 static true_type __test(int);
966 template<typename, typename>
967 static false_type __test(...);
970 template<typename _Tp, typename _Arg>
971 struct __is_direct_constructible_impl
972 : public __do_is_direct_constructible_impl
974 typedef decltype(__test<_Tp, _Arg>(0)) type;
977 template<typename _Tp, typename _Arg>
978 struct __is_direct_constructible_new_safe
979 : public __and_<is_destructible<_Tp>,
980 __is_direct_constructible_impl<_Tp, _Arg>>
983 template<typename, typename>
986 template<typename, typename>
990 struct remove_reference;
992 template<typename _From, typename _To, bool
993 = __not_<__or_<is_void<_From>,
994 is_function<_From>>>::value>
995 struct __is_base_to_derived_ref;
997 template<typename _Tp, typename... _Args>
998 struct is_constructible;
1000 // Detect whether we have a downcast situation during
1001 // reference binding.
1002 template<typename _From, typename _To>
1003 struct __is_base_to_derived_ref<_From, _To, true>
1005 typedef typename remove_cv<typename remove_reference<_From
1006 >::type>::type __src_t;
1007 typedef typename remove_cv<typename remove_reference<_To
1008 >::type>::type __dst_t;
1009 typedef __and_<__not_<is_same<__src_t, __dst_t>>,
1010 is_base_of<__src_t, __dst_t>,
1011 __not_<is_constructible<__dst_t, _From>>> type;
1012 static constexpr bool value = type::value;
1015 template<typename _From, typename _To>
1016 struct __is_base_to_derived_ref<_From, _To, false>
1020 template<typename _From, typename _To, bool
1021 = __and_<is_lvalue_reference<_From>,
1022 is_rvalue_reference<_To>>::value>
1023 struct __is_lvalue_to_rvalue_ref;
1025 // Detect whether we have an lvalue of non-function type
1026 // bound to a reference-compatible rvalue-reference.
1027 template<typename _From, typename _To>
1028 struct __is_lvalue_to_rvalue_ref<_From, _To, true>
1030 typedef typename remove_cv<typename remove_reference<
1031 _From>::type>::type __src_t;
1032 typedef typename remove_cv<typename remove_reference<
1033 _To>::type>::type __dst_t;
1034 typedef __and_<__not_<is_function<__src_t>>,
1035 __or_<is_same<__src_t, __dst_t>,
1036 is_base_of<__dst_t, __src_t>>> type;
1037 static constexpr bool value = type::value;
1040 template<typename _From, typename _To>
1041 struct __is_lvalue_to_rvalue_ref<_From, _To, false>
1045 // Here we handle direct-initialization to a reference type as
1046 // equivalent to a static_cast modulo overshooting conversions.
1047 // These are restricted to the following conversions:
1048 // a) A base class value to a derived class reference
1049 // b) An lvalue to an rvalue-reference of reference-compatible
1050 // types that are not functions
1051 template<typename _Tp, typename _Arg>
1052 struct __is_direct_constructible_ref_cast
1053 : public __and_<__is_static_castable<_Arg, _Tp>,
1054 __not_<__or_<__is_base_to_derived_ref<_Arg, _Tp>,
1055 __is_lvalue_to_rvalue_ref<_Arg, _Tp>
1059 template<typename _Tp, typename _Arg>
1060 struct __is_direct_constructible_new
1061 : public conditional<is_reference<_Tp>::value,
1062 __is_direct_constructible_ref_cast<_Tp, _Arg>,
1063 __is_direct_constructible_new_safe<_Tp, _Arg>
1067 template<typename _Tp, typename _Arg>
1068 struct __is_direct_constructible
1069 : public __is_direct_constructible_new<_Tp, _Arg>::type
1072 // Since default-construction and binary direct-initialization have
1073 // been handled separately, the implementation of the remaining
1074 // n-ary construction cases is rather straightforward. We can use
1075 // here a functional cast, because array types are excluded anyway
1076 // and this form is never interpreted as a C cast.
1077 struct __do_is_nary_constructible_impl
1079 template<typename _Tp, typename... _Args, typename
1080 = decltype(_Tp(declval<_Args>()...))>
1081 static true_type __test(int);
1083 template<typename, typename...>
1084 static false_type __test(...);
1087 template<typename _Tp, typename... _Args>
1088 struct __is_nary_constructible_impl
1089 : public __do_is_nary_constructible_impl
1091 typedef decltype(__test<_Tp, _Args...>(0)) type;
1094 template<typename _Tp, typename... _Args>
1095 struct __is_nary_constructible
1096 : public __is_nary_constructible_impl<_Tp, _Args...>::type
1098 static_assert(sizeof...(_Args) > 1,
1099 "Only useful for > 1 arguments");
1102 template<typename _Tp, typename... _Args>
1103 struct __is_constructible_impl
1104 : public __is_nary_constructible<_Tp, _Args...>
1107 template<typename _Tp, typename _Arg>
1108 struct __is_constructible_impl<_Tp, _Arg>
1109 : public __is_direct_constructible<_Tp, _Arg>
1112 template<typename _Tp>
1113 struct __is_constructible_impl<_Tp>
1114 : public is_default_constructible<_Tp>
1117 /// is_constructible
1118 template<typename _Tp, typename... _Args>
1119 struct is_constructible
1120 : public __is_constructible_impl<_Tp, _Args...>::type
1123 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1124 struct __is_copy_constructible_impl;
1126 template<typename _Tp>
1127 struct __is_copy_constructible_impl<_Tp, false>
1128 : public false_type { };
1130 template<typename _Tp>
1131 struct __is_copy_constructible_impl<_Tp, true>
1132 : public is_constructible<_Tp, const _Tp&>
1135 /// is_copy_constructible
1136 template<typename _Tp>
1137 struct is_copy_constructible
1138 : public __is_copy_constructible_impl<_Tp>
1141 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1142 struct __is_move_constructible_impl;
1144 template<typename _Tp>
1145 struct __is_move_constructible_impl<_Tp, false>
1146 : public false_type { };
1148 template<typename _Tp>
1149 struct __is_move_constructible_impl<_Tp, true>
1150 : public is_constructible<_Tp, _Tp&&>
1153 /// is_move_constructible
1154 template<typename _Tp>
1155 struct is_move_constructible
1156 : public __is_move_constructible_impl<_Tp>
1159 template<typename _Tp>
1160 struct __is_nt_default_constructible_atom
1161 : public integral_constant<bool, noexcept(_Tp())>
1164 template<typename _Tp, bool = is_array<_Tp>::value>
1165 struct __is_nt_default_constructible_impl;
1167 template<typename _Tp>
1168 struct __is_nt_default_constructible_impl<_Tp, true>
1169 : public __and_<__is_array_known_bounds<_Tp>,
1170 __is_nt_default_constructible_atom<typename
1171 remove_all_extents<_Tp>::type>>
1174 template<typename _Tp>
1175 struct __is_nt_default_constructible_impl<_Tp, false>
1176 : public __is_nt_default_constructible_atom<_Tp>
1179 /// is_nothrow_default_constructible
1180 template<typename _Tp>
1181 struct is_nothrow_default_constructible
1182 : public __and_<is_default_constructible<_Tp>,
1183 __is_nt_default_constructible_impl<_Tp>>
1186 template<typename _Tp, typename... _Args>
1187 struct __is_nt_constructible_impl
1188 : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
1191 template<typename _Tp, typename _Arg>
1192 struct __is_nt_constructible_impl<_Tp, _Arg>
1193 : public integral_constant<bool,
1194 noexcept(static_cast<_Tp>(declval<_Arg>()))>
1197 template<typename _Tp>
1198 struct __is_nt_constructible_impl<_Tp>
1199 : public is_nothrow_default_constructible<_Tp>
1202 /// is_nothrow_constructible
1203 template<typename _Tp, typename... _Args>
1204 struct is_nothrow_constructible
1205 : public __and_<is_constructible<_Tp, _Args...>,
1206 __is_nt_constructible_impl<_Tp, _Args...>>
1209 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1210 struct __is_nothrow_copy_constructible_impl;
1212 template<typename _Tp>
1213 struct __is_nothrow_copy_constructible_impl<_Tp, false>
1214 : public false_type { };
1216 template<typename _Tp>
1217 struct __is_nothrow_copy_constructible_impl<_Tp, true>
1218 : public is_nothrow_constructible<_Tp, const _Tp&>
1221 /// is_nothrow_copy_constructible
1222 template<typename _Tp>
1223 struct is_nothrow_copy_constructible
1224 : public __is_nothrow_copy_constructible_impl<_Tp>
1227 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1228 struct __is_nothrow_move_constructible_impl;
1230 template<typename _Tp>
1231 struct __is_nothrow_move_constructible_impl<_Tp, false>
1232 : public false_type { };
1234 template<typename _Tp>
1235 struct __is_nothrow_move_constructible_impl<_Tp, true>
1236 : public is_nothrow_constructible<_Tp, _Tp&&>
1239 /// is_nothrow_move_constructible
1240 template<typename _Tp>
1241 struct is_nothrow_move_constructible
1242 : public __is_nothrow_move_constructible_impl<_Tp>
1245 template<typename _Tp, typename _Up>
1246 class __is_assignable_helper
1248 template<typename _Tp1, typename _Up1,
1249 typename = decltype(declval<_Tp1>() = declval<_Up1>())>
1253 template<typename, typename>
1258 typedef decltype(__test<_Tp, _Up>(0)) type;
1262 template<typename _Tp, typename _Up>
1263 struct is_assignable
1264 : public __is_assignable_helper<_Tp, _Up>::type
1267 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1268 struct __is_copy_assignable_impl;
1270 template<typename _Tp>
1271 struct __is_copy_assignable_impl<_Tp, false>
1272 : public false_type { };
1274 template<typename _Tp>
1275 struct __is_copy_assignable_impl<_Tp, true>
1276 : public is_assignable<_Tp&, const _Tp&>
1279 /// is_copy_assignable
1280 template<typename _Tp>
1281 struct is_copy_assignable
1282 : public __is_copy_assignable_impl<_Tp>
1285 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1286 struct __is_move_assignable_impl;
1288 template<typename _Tp>
1289 struct __is_move_assignable_impl<_Tp, false>
1290 : public false_type { };
1292 template<typename _Tp>
1293 struct __is_move_assignable_impl<_Tp, true>
1294 : public is_assignable<_Tp&, _Tp&&>
1297 /// is_move_assignable
1298 template<typename _Tp>
1299 struct is_move_assignable
1300 : public __is_move_assignable_impl<_Tp>
1303 template<typename _Tp, typename _Up>
1304 struct __is_nt_assignable_impl
1305 : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Up>())>
1308 /// is_nothrow_assignable
1309 template<typename _Tp, typename _Up>
1310 struct is_nothrow_assignable
1311 : public __and_<is_assignable<_Tp, _Up>,
1312 __is_nt_assignable_impl<_Tp, _Up>>
1315 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1316 struct __is_nt_copy_assignable_impl;
1318 template<typename _Tp>
1319 struct __is_nt_copy_assignable_impl<_Tp, false>
1320 : public false_type { };
1322 template<typename _Tp>
1323 struct __is_nt_copy_assignable_impl<_Tp, true>
1324 : public is_nothrow_assignable<_Tp&, const _Tp&>
1327 /// is_nothrow_copy_assignable
1328 template<typename _Tp>
1329 struct is_nothrow_copy_assignable
1330 : public __is_nt_copy_assignable_impl<_Tp>
1333 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1334 struct __is_nt_move_assignable_impl;
1336 template<typename _Tp>
1337 struct __is_nt_move_assignable_impl<_Tp, false>
1338 : public false_type { };
1340 template<typename _Tp>
1341 struct __is_nt_move_assignable_impl<_Tp, true>
1342 : public is_nothrow_assignable<_Tp&, _Tp&&>
1345 /// is_nothrow_move_assignable
1346 template<typename _Tp>
1347 struct is_nothrow_move_assignable
1348 : public __is_nt_move_assignable_impl<_Tp>
1351 /// is_trivially_constructible
1352 template<typename _Tp, typename... _Args>
1353 struct is_trivially_constructible
1354 : public __and_<is_constructible<_Tp, _Args...>, integral_constant<bool,
1355 __is_trivially_constructible(_Tp, _Args...)>>
1358 /// is_trivially_default_constructible
1359 template<typename _Tp>
1360 struct is_trivially_default_constructible
1361 : public is_trivially_constructible<_Tp>::type
1364 struct __do_is_implicitly_default_constructible_impl
1366 template <typename _Tp>
1367 static void __helper(const _Tp&);
1369 template <typename _Tp>
1370 static true_type __test(const _Tp&,
1371 decltype(__helper<const _Tp&>({}))* = 0);
1373 static false_type __test(...);
1376 template<typename _Tp>
1377 struct __is_implicitly_default_constructible_impl
1378 : public __do_is_implicitly_default_constructible_impl
1380 typedef decltype(__test(declval<_Tp>())) type;
1383 template<typename _Tp>
1384 struct __is_implicitly_default_constructible_safe
1385 : public __is_implicitly_default_constructible_impl<_Tp>::type
1388 template <typename _Tp>
1389 struct __is_implicitly_default_constructible
1390 : public __and_<is_default_constructible<_Tp>,
1391 __is_implicitly_default_constructible_safe<_Tp>>
1394 /// is_trivially_copy_constructible
1395 template<typename _Tp>
1396 struct is_trivially_copy_constructible
1397 : public __and_<is_copy_constructible<_Tp>,
1398 integral_constant<bool,
1399 __is_trivially_constructible(_Tp, const _Tp&)>>
1402 /// is_trivially_move_constructible
1403 template<typename _Tp>
1404 struct is_trivially_move_constructible
1405 : public __and_<is_move_constructible<_Tp>,
1406 integral_constant<bool,
1407 __is_trivially_constructible(_Tp, _Tp&&)>>
1410 /// is_trivially_assignable
1411 template<typename _Tp, typename _Up>
1412 struct is_trivially_assignable
1413 : public __and_<is_assignable<_Tp, _Up>,
1414 integral_constant<bool,
1415 __is_trivially_assignable(_Tp, _Up)>>
1418 /// is_trivially_copy_assignable
1419 template<typename _Tp>
1420 struct is_trivially_copy_assignable
1421 : public __and_<is_copy_assignable<_Tp>,
1422 integral_constant<bool,
1423 __is_trivially_assignable(_Tp&, const _Tp&)>>
1426 /// is_trivially_move_assignable
1427 template<typename _Tp>
1428 struct is_trivially_move_assignable
1429 : public __and_<is_move_assignable<_Tp>,
1430 integral_constant<bool,
1431 __is_trivially_assignable(_Tp&, _Tp&&)>>
1434 /// is_trivially_destructible
1435 template<typename _Tp>
1436 struct is_trivially_destructible
1437 : public __and_<is_destructible<_Tp>, integral_constant<bool,
1438 __has_trivial_destructor(_Tp)>>
1441 /// has_trivial_default_constructor (temporary legacy)
1442 template<typename _Tp>
1443 struct has_trivial_default_constructor
1444 : public integral_constant<bool, __has_trivial_constructor(_Tp)>
1445 { } _GLIBCXX_DEPRECATED;
1447 /// has_trivial_copy_constructor (temporary legacy)
1448 template<typename _Tp>
1449 struct has_trivial_copy_constructor
1450 : public integral_constant<bool, __has_trivial_copy(_Tp)>
1451 { } _GLIBCXX_DEPRECATED;
1453 /// has_trivial_copy_assign (temporary legacy)
1454 template<typename _Tp>
1455 struct has_trivial_copy_assign
1456 : public integral_constant<bool, __has_trivial_assign(_Tp)>
1457 { } _GLIBCXX_DEPRECATED;
1459 /// has_virtual_destructor
1460 template<typename _Tp>
1461 struct has_virtual_destructor
1462 : public integral_constant<bool, __has_virtual_destructor(_Tp)>
1466 // type property queries.
1469 template<typename _Tp>
1471 : public integral_constant<std::size_t, __alignof__(_Tp)> { };
1476 : public integral_constant<std::size_t, 0> { };
1478 template<typename _Tp, std::size_t _Size>
1479 struct rank<_Tp[_Size]>
1480 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1482 template<typename _Tp>
1484 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1487 template<typename, unsigned _Uint>
1489 : public integral_constant<std::size_t, 0> { };
1491 template<typename _Tp, unsigned _Uint, std::size_t _Size>
1492 struct extent<_Tp[_Size], _Uint>
1493 : public integral_constant<std::size_t,
1494 _Uint == 0 ? _Size : extent<_Tp,
1498 template<typename _Tp, unsigned _Uint>
1499 struct extent<_Tp[], _Uint>
1500 : public integral_constant<std::size_t,
1501 _Uint == 0 ? 0 : extent<_Tp,
1509 template<typename, typename>
1511 : public false_type { };
1513 template<typename _Tp>
1514 struct is_same<_Tp, _Tp>
1515 : public true_type { };
1518 template<typename _Base, typename _Derived>
1520 : public integral_constant<bool, __is_base_of(_Base, _Derived)>
1523 template<typename _From, typename _To,
1524 bool = __or_<is_void<_From>, is_function<_To>,
1525 is_array<_To>>::value>
1526 struct __is_convertible_helper
1527 { typedef typename is_void<_To>::type type; };
1529 template<typename _From, typename _To>
1530 class __is_convertible_helper<_From, _To, false>
1532 template<typename _To1>
1533 static void __test_aux(_To1);
1535 template<typename _From1, typename _To1,
1536 typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
1540 template<typename, typename>
1545 typedef decltype(__test<_From, _To>(0)) type;
1550 template<typename _From, typename _To>
1551 struct is_convertible
1552 : public __is_convertible_helper<_From, _To>::type
1556 // Const-volatile modifications.
1559 template<typename _Tp>
1561 { typedef _Tp type; };
1563 template<typename _Tp>
1564 struct remove_const<_Tp const>
1565 { typedef _Tp type; };
1568 template<typename _Tp>
1569 struct remove_volatile
1570 { typedef _Tp type; };
1572 template<typename _Tp>
1573 struct remove_volatile<_Tp volatile>
1574 { typedef _Tp type; };
1577 template<typename _Tp>
1581 remove_const<typename remove_volatile<_Tp>::type>::type type;
1585 template<typename _Tp>
1587 { typedef _Tp const type; };
1590 template<typename _Tp>
1592 { typedef _Tp volatile type; };
1595 template<typename _Tp>
1599 add_const<typename add_volatile<_Tp>::type>::type type;
1602 #if __cplusplus > 201103L
1604 #define __cpp_lib_transformation_trait_aliases 201304
1606 /// Alias template for remove_const
1607 template<typename _Tp>
1608 using remove_const_t = typename remove_const<_Tp>::type;
1610 /// Alias template for remove_volatile
1611 template<typename _Tp>
1612 using remove_volatile_t = typename remove_volatile<_Tp>::type;
1614 /// Alias template for remove_cv
1615 template<typename _Tp>
1616 using remove_cv_t = typename remove_cv<_Tp>::type;
1618 /// Alias template for add_const
1619 template<typename _Tp>
1620 using add_const_t = typename add_const<_Tp>::type;
1622 /// Alias template for add_volatile
1623 template<typename _Tp>
1624 using add_volatile_t = typename add_volatile<_Tp>::type;
1626 /// Alias template for add_cv
1627 template<typename _Tp>
1628 using add_cv_t = typename add_cv<_Tp>::type;
1631 // Reference transformations.
1633 /// remove_reference
1634 template<typename _Tp>
1635 struct remove_reference
1636 { typedef _Tp type; };
1638 template<typename _Tp>
1639 struct remove_reference<_Tp&>
1640 { typedef _Tp type; };
1642 template<typename _Tp>
1643 struct remove_reference<_Tp&&>
1644 { typedef _Tp type; };
1646 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1647 struct __add_lvalue_reference_helper
1648 { typedef _Tp type; };
1650 template<typename _Tp>
1651 struct __add_lvalue_reference_helper<_Tp, true>
1652 { typedef _Tp& type; };
1654 /// add_lvalue_reference
1655 template<typename _Tp>
1656 struct add_lvalue_reference
1657 : public __add_lvalue_reference_helper<_Tp>
1660 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1661 struct __add_rvalue_reference_helper
1662 { typedef _Tp type; };
1664 template<typename _Tp>
1665 struct __add_rvalue_reference_helper<_Tp, true>
1666 { typedef _Tp&& type; };
1668 /// add_rvalue_reference
1669 template<typename _Tp>
1670 struct add_rvalue_reference
1671 : public __add_rvalue_reference_helper<_Tp>
1674 #if __cplusplus > 201103L
1675 /// Alias template for remove_reference
1676 template<typename _Tp>
1677 using remove_reference_t = typename remove_reference<_Tp>::type;
1679 /// Alias template for add_lvalue_reference
1680 template<typename _Tp>
1681 using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
1683 /// Alias template for add_rvalue_reference
1684 template<typename _Tp>
1685 using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
1688 // Sign modifications.
1690 // Utility for constructing identically cv-qualified types.
1691 template<typename _Unqualified, bool _IsConst, bool _IsVol>
1692 struct __cv_selector;
1694 template<typename _Unqualified>
1695 struct __cv_selector<_Unqualified, false, false>
1696 { typedef _Unqualified __type; };
1698 template<typename _Unqualified>
1699 struct __cv_selector<_Unqualified, false, true>
1700 { typedef volatile _Unqualified __type; };
1702 template<typename _Unqualified>
1703 struct __cv_selector<_Unqualified, true, false>
1704 { typedef const _Unqualified __type; };
1706 template<typename _Unqualified>
1707 struct __cv_selector<_Unqualified, true, true>
1708 { typedef const volatile _Unqualified __type; };
1710 template<typename _Qualified, typename _Unqualified,
1711 bool _IsConst = is_const<_Qualified>::value,
1712 bool _IsVol = is_volatile<_Qualified>::value>
1713 class __match_cv_qualifiers
1715 typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
1718 typedef typename __match::__type __type;
1721 // Utility for finding the unsigned versions of signed integral types.
1722 template<typename _Tp>
1723 struct __make_unsigned
1724 { typedef _Tp __type; };
1727 struct __make_unsigned<char>
1728 { typedef unsigned char __type; };
1731 struct __make_unsigned<signed char>
1732 { typedef unsigned char __type; };
1735 struct __make_unsigned<short>
1736 { typedef unsigned short __type; };
1739 struct __make_unsigned<int>
1740 { typedef unsigned int __type; };
1743 struct __make_unsigned<long>
1744 { typedef unsigned long __type; };
1747 struct __make_unsigned<long long>
1748 { typedef unsigned long long __type; };
1750 #if defined(_GLIBCXX_USE_WCHAR_T) && !defined(__WCHAR_UNSIGNED__)
1752 struct __make_unsigned<wchar_t> : __make_unsigned<__WCHAR_TYPE__>
1756 #if defined(__GLIBCXX_TYPE_INT_N_0)
1758 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_0>
1759 { typedef unsigned __GLIBCXX_TYPE_INT_N_0 __type; };
1761 #if defined(__GLIBCXX_TYPE_INT_N_1)
1763 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_1>
1764 { typedef unsigned __GLIBCXX_TYPE_INT_N_1 __type; };
1766 #if defined(__GLIBCXX_TYPE_INT_N_2)
1768 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_2>
1769 { typedef unsigned __GLIBCXX_TYPE_INT_N_2 __type; };
1771 #if defined(__GLIBCXX_TYPE_INT_N_3)
1773 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_3>
1774 { typedef unsigned __GLIBCXX_TYPE_INT_N_3 __type; };
1777 // Select between integral and enum: not possible to be both.
1778 template<typename _Tp,
1779 bool _IsInt = is_integral<_Tp>::value,
1780 bool _IsEnum = is_enum<_Tp>::value>
1781 class __make_unsigned_selector;
1783 template<typename _Tp>
1784 class __make_unsigned_selector<_Tp, true, false>
1786 typedef __make_unsigned<typename remove_cv<_Tp>::type> __unsignedt;
1787 typedef typename __unsignedt::__type __unsigned_type;
1788 typedef __match_cv_qualifiers<_Tp, __unsigned_type> __cv_unsigned;
1791 typedef typename __cv_unsigned::__type __type;
1794 template<typename _Tp>
1795 class __make_unsigned_selector<_Tp, false, true>
1797 // With -fshort-enums, an enum may be as small as a char.
1798 typedef unsigned char __smallest;
1799 static const bool __b0 = sizeof(_Tp) <= sizeof(__smallest);
1800 static const bool __b1 = sizeof(_Tp) <= sizeof(unsigned short);
1801 static const bool __b2 = sizeof(_Tp) <= sizeof(unsigned int);
1802 static const bool __b3 = sizeof(_Tp) <= sizeof(unsigned long);
1803 typedef conditional<__b3, unsigned long, unsigned long long> __cond3;
1804 typedef typename __cond3::type __cond3_type;
1805 typedef conditional<__b2, unsigned int, __cond3_type> __cond2;
1806 typedef typename __cond2::type __cond2_type;
1807 typedef conditional<__b1, unsigned short, __cond2_type> __cond1;
1808 typedef typename __cond1::type __cond1_type;
1810 typedef typename conditional<__b0, __smallest, __cond1_type>::type
1812 typedef __match_cv_qualifiers<_Tp, __unsigned_type> __cv_unsigned;
1815 typedef typename __cv_unsigned::__type __type;
1818 // Given an integral/enum type, return the corresponding unsigned
1820 // Primary template.
1822 template<typename _Tp>
1823 struct make_unsigned
1824 { typedef typename __make_unsigned_selector<_Tp>::__type type; };
1826 // Integral, but don't define.
1828 struct make_unsigned<bool>;
1831 // Utility for finding the signed versions of unsigned integral types.
1832 template<typename _Tp>
1833 struct __make_signed
1834 { typedef _Tp __type; };
1837 struct __make_signed<char>
1838 { typedef signed char __type; };
1841 struct __make_signed<unsigned char>
1842 { typedef signed char __type; };
1845 struct __make_signed<unsigned short>
1846 { typedef signed short __type; };
1849 struct __make_signed<unsigned int>
1850 { typedef signed int __type; };
1853 struct __make_signed<unsigned long>
1854 { typedef signed long __type; };
1857 struct __make_signed<unsigned long long>
1858 { typedef signed long long __type; };
1860 #if defined(_GLIBCXX_USE_WCHAR_T) && defined(__WCHAR_UNSIGNED__)
1862 struct __make_signed<wchar_t> : __make_signed<__WCHAR_TYPE__>
1866 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
1868 struct __make_signed<char16_t> : __make_signed<uint_least16_t>
1871 struct __make_signed<char32_t> : __make_signed<uint_least32_t>
1875 #if defined(__GLIBCXX_TYPE_INT_N_0)
1877 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_0>
1878 { typedef __GLIBCXX_TYPE_INT_N_0 __type; };
1880 #if defined(__GLIBCXX_TYPE_INT_N_1)
1882 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_1>
1883 { typedef __GLIBCXX_TYPE_INT_N_1 __type; };
1885 #if defined(__GLIBCXX_TYPE_INT_N_2)
1887 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_2>
1888 { typedef __GLIBCXX_TYPE_INT_N_2 __type; };
1890 #if defined(__GLIBCXX_TYPE_INT_N_3)
1892 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_3>
1893 { typedef __GLIBCXX_TYPE_INT_N_3 __type; };
1896 // Select between integral and enum: not possible to be both.
1897 template<typename _Tp,
1898 bool _IsInt = is_integral<_Tp>::value,
1899 bool _IsEnum = is_enum<_Tp>::value>
1900 class __make_signed_selector;
1902 template<typename _Tp>
1903 class __make_signed_selector<_Tp, true, false>
1905 typedef __make_signed<typename remove_cv<_Tp>::type> __signedt;
1906 typedef typename __signedt::__type __signed_type;
1907 typedef __match_cv_qualifiers<_Tp, __signed_type> __cv_signed;
1910 typedef typename __cv_signed::__type __type;
1913 template<typename _Tp>
1914 class __make_signed_selector<_Tp, false, true>
1916 typedef typename __make_unsigned_selector<_Tp>::__type __unsigned_type;
1919 typedef typename __make_signed_selector<__unsigned_type>::__type __type;
1922 // Given an integral/enum type, return the corresponding signed
1924 // Primary template.
1926 template<typename _Tp>
1928 { typedef typename __make_signed_selector<_Tp>::__type type; };
1930 // Integral, but don't define.
1932 struct make_signed<bool>;
1934 #if __cplusplus > 201103L
1935 /// Alias template for make_signed
1936 template<typename _Tp>
1937 using make_signed_t = typename make_signed<_Tp>::type;
1939 /// Alias template for make_unsigned
1940 template<typename _Tp>
1941 using make_unsigned_t = typename make_unsigned<_Tp>::type;
1944 // Array modifications.
1947 template<typename _Tp>
1948 struct remove_extent
1949 { typedef _Tp type; };
1951 template<typename _Tp, std::size_t _Size>
1952 struct remove_extent<_Tp[_Size]>
1953 { typedef _Tp type; };
1955 template<typename _Tp>
1956 struct remove_extent<_Tp[]>
1957 { typedef _Tp type; };
1959 /// remove_all_extents
1960 template<typename _Tp>
1961 struct remove_all_extents
1962 { typedef _Tp type; };
1964 template<typename _Tp, std::size_t _Size>
1965 struct remove_all_extents<_Tp[_Size]>
1966 { typedef typename remove_all_extents<_Tp>::type type; };
1968 template<typename _Tp>
1969 struct remove_all_extents<_Tp[]>
1970 { typedef typename remove_all_extents<_Tp>::type type; };
1972 #if __cplusplus > 201103L
1973 /// Alias template for remove_extent
1974 template<typename _Tp>
1975 using remove_extent_t = typename remove_extent<_Tp>::type;
1977 /// Alias template for remove_all_extents
1978 template<typename _Tp>
1979 using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
1982 // Pointer modifications.
1984 template<typename _Tp, typename>
1985 struct __remove_pointer_helper
1986 { typedef _Tp type; };
1988 template<typename _Tp, typename _Up>
1989 struct __remove_pointer_helper<_Tp, _Up*>
1990 { typedef _Up type; };
1993 template<typename _Tp>
1994 struct remove_pointer
1995 : public __remove_pointer_helper<_Tp, typename remove_cv<_Tp>::type>
1999 template<typename _Tp, bool = __or_<__is_referenceable<_Tp>,
2000 is_void<_Tp>>::value>
2001 struct __add_pointer_helper
2002 { typedef _Tp type; };
2004 template<typename _Tp>
2005 struct __add_pointer_helper<_Tp, true>
2006 { typedef typename remove_reference<_Tp>::type* type; };
2008 template<typename _Tp>
2010 : public __add_pointer_helper<_Tp>
2013 #if __cplusplus > 201103L
2014 /// Alias template for remove_pointer
2015 template<typename _Tp>
2016 using remove_pointer_t = typename remove_pointer<_Tp>::type;
2018 /// Alias template for add_pointer
2019 template<typename _Tp>
2020 using add_pointer_t = typename add_pointer<_Tp>::type;
2023 template<std::size_t _Len>
2024 struct __aligned_storage_msa
2028 unsigned char __data[_Len];
2029 struct __attribute__((__aligned__)) { } __align;
2034 * @brief Alignment type.
2036 * The value of _Align is a default-alignment which shall be the
2037 * most stringent alignment requirement for any C++ object type
2038 * whose size is no greater than _Len (3.9). The member typedef
2039 * type shall be a POD type suitable for use as uninitialized
2040 * storage for any object whose size is at most _Len and whose
2041 * alignment is a divisor of _Align.
2043 template<std::size_t _Len, std::size_t _Align =
2044 __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2045 struct aligned_storage
2049 unsigned char __data[_Len];
2050 struct __attribute__((__aligned__((_Align)))) { } __align;
2054 template <typename... _Types>
2055 struct __strictest_alignment
2057 static const size_t _S_alignment = 0;
2058 static const size_t _S_size = 0;
2061 template <typename _Tp, typename... _Types>
2062 struct __strictest_alignment<_Tp, _Types...>
2064 static const size_t _S_alignment =
2065 alignof(_Tp) > __strictest_alignment<_Types...>::_S_alignment
2066 ? alignof(_Tp) : __strictest_alignment<_Types...>::_S_alignment;
2067 static const size_t _S_size =
2068 sizeof(_Tp) > __strictest_alignment<_Types...>::_S_size
2069 ? sizeof(_Tp) : __strictest_alignment<_Types...>::_S_size;
2073 * @brief Provide aligned storage for types.
2075 * [meta.trans.other]
2077 * Provides aligned storage for any of the provided types of at
2080 * @see aligned_storage
2082 template <size_t _Len, typename... _Types>
2083 struct aligned_union
2086 static_assert(sizeof...(_Types) != 0, "At least one type is required");
2088 using __strictest = __strictest_alignment<_Types...>;
2089 static const size_t _S_len = _Len > __strictest::_S_size
2090 ? _Len : __strictest::_S_size;
2092 /// The value of the strictest alignment of _Types.
2093 static const size_t alignment_value = __strictest::_S_alignment;
2095 typedef typename aligned_storage<_S_len, alignment_value>::type type;
2098 template <size_t _Len, typename... _Types>
2099 const size_t aligned_union<_Len, _Types...>::alignment_value;
2101 // Decay trait for arrays and functions, used for perfect forwarding
2102 // in make_pair, make_tuple, etc.
2103 template<typename _Up,
2104 bool _IsArray = is_array<_Up>::value,
2105 bool _IsFunction = is_function<_Up>::value>
2106 struct __decay_selector;
2109 template<typename _Up>
2110 struct __decay_selector<_Up, false, false>
2111 { typedef typename remove_cv<_Up>::type __type; };
2113 template<typename _Up>
2114 struct __decay_selector<_Up, true, false>
2115 { typedef typename remove_extent<_Up>::type* __type; };
2117 template<typename _Up>
2118 struct __decay_selector<_Up, false, true>
2119 { typedef typename add_pointer<_Up>::type __type; };
2122 template<typename _Tp>
2125 typedef typename remove_reference<_Tp>::type __remove_type;
2128 typedef typename __decay_selector<__remove_type>::__type type;
2131 template<typename _Tp>
2132 class reference_wrapper;
2134 // Helper which adds a reference to a type when given a reference_wrapper
2135 template<typename _Tp>
2136 struct __strip_reference_wrapper
2141 template<typename _Tp>
2142 struct __strip_reference_wrapper<reference_wrapper<_Tp> >
2144 typedef _Tp& __type;
2147 template<typename _Tp>
2148 struct __decay_and_strip
2150 typedef typename __strip_reference_wrapper<
2151 typename decay<_Tp>::type>::__type __type;
2155 // Primary template.
2156 /// Define a member typedef @c type only if a boolean constant is true.
2157 template<bool, typename _Tp = void>
2161 // Partial specialization for true.
2162 template<typename _Tp>
2163 struct enable_if<true, _Tp>
2164 { typedef _Tp type; };
2166 template<typename... _Cond>
2167 using _Require = typename enable_if<__and_<_Cond...>::value>::type;
2169 // Primary template.
2170 /// Define a member typedef @c type to one of two argument types.
2171 template<bool _Cond, typename _Iftrue, typename _Iffalse>
2173 { typedef _Iftrue type; };
2175 // Partial specialization for false.
2176 template<typename _Iftrue, typename _Iffalse>
2177 struct conditional<false, _Iftrue, _Iffalse>
2178 { typedef _Iffalse type; };
2181 template<typename... _Tp>
2184 // Sfinae-friendly common_type implementation:
2186 struct __do_common_type_impl
2188 template<typename _Tp, typename _Up>
2189 static __success_type<typename decay<decltype
2190 (true ? std::declval<_Tp>()
2191 : std::declval<_Up>())>::type> _S_test(int);
2193 template<typename, typename>
2194 static __failure_type _S_test(...);
2197 template<typename _Tp, typename _Up>
2198 struct __common_type_impl
2199 : private __do_common_type_impl
2201 typedef decltype(_S_test<_Tp, _Up>(0)) type;
2204 struct __do_member_type_wrapper
2206 template<typename _Tp>
2207 static __success_type<typename _Tp::type> _S_test(int);
2210 static __failure_type _S_test(...);
2213 template<typename _Tp>
2214 struct __member_type_wrapper
2215 : private __do_member_type_wrapper
2217 typedef decltype(_S_test<_Tp>(0)) type;
2220 template<typename _CTp, typename... _Args>
2221 struct __expanded_common_type_wrapper
2223 typedef common_type<typename _CTp::type, _Args...> type;
2226 template<typename... _Args>
2227 struct __expanded_common_type_wrapper<__failure_type, _Args...>
2228 { typedef __failure_type type; };
2230 template<typename _Tp>
2231 struct common_type<_Tp>
2232 { typedef typename decay<_Tp>::type type; };
2234 template<typename _Tp, typename _Up>
2235 struct common_type<_Tp, _Up>
2236 : public __common_type_impl<_Tp, _Up>::type
2239 template<typename _Tp, typename _Up, typename... _Vp>
2240 struct common_type<_Tp, _Up, _Vp...>
2241 : public __expanded_common_type_wrapper<typename __member_type_wrapper<
2242 common_type<_Tp, _Up>>::type, _Vp...>::type
2245 /// The underlying type of an enum.
2246 template<typename _Tp>
2247 struct underlying_type
2249 typedef __underlying_type(_Tp) type;
2252 template<typename _Tp>
2253 struct __declval_protector
2255 static const bool __stop = false;
2256 static typename add_rvalue_reference<_Tp>::type __delegate();
2259 template<typename _Tp>
2260 inline typename add_rvalue_reference<_Tp>::type
2263 static_assert(__declval_protector<_Tp>::__stop,
2264 "declval() must not be used!");
2265 return __declval_protector<_Tp>::__delegate();
2269 template<typename _Signature>
2272 // Sfinae-friendly result_of implementation:
2274 #define __cpp_lib_result_of_sfinae 201210
2276 struct __invoke_memfun_ref { };
2277 struct __invoke_memfun_deref { };
2278 struct __invoke_memobj_ref { };
2279 struct __invoke_memobj_deref { };
2280 struct __invoke_other { };
2282 // Associate a tag type with a specialization of __success_type.
2283 template<typename _Tp, typename _Tag>
2284 struct __result_of_success : __success_type<_Tp>
2285 { using __invoke_type = _Tag; };
2287 // [func.require] paragraph 1 bullet 1:
2288 struct __result_of_memfun_ref_impl
2290 template<typename _Fp, typename _Tp1, typename... _Args>
2291 static __result_of_success<decltype(
2292 (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
2293 ), __invoke_memfun_ref> _S_test(int);
2295 template<typename...>
2296 static __failure_type _S_test(...);
2299 template<typename _MemPtr, typename _Arg, typename... _Args>
2300 struct __result_of_memfun_ref
2301 : private __result_of_memfun_ref_impl
2303 typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2306 // [func.require] paragraph 1 bullet 2:
2307 struct __result_of_memfun_deref_impl
2309 template<typename _Fp, typename _Tp1, typename... _Args>
2310 static __result_of_success<decltype(
2311 ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
2312 ), __invoke_memfun_deref> _S_test(int);
2314 template<typename...>
2315 static __failure_type _S_test(...);
2318 template<typename _MemPtr, typename _Arg, typename... _Args>
2319 struct __result_of_memfun_deref
2320 : private __result_of_memfun_deref_impl
2322 typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2325 // [func.require] paragraph 1 bullet 3:
2326 struct __result_of_memobj_ref_impl
2328 template<typename _Fp, typename _Tp1>
2329 static __result_of_success<decltype(
2330 std::declval<_Tp1>().*std::declval<_Fp>()
2331 ), __invoke_memobj_ref> _S_test(int);
2333 template<typename, typename>
2334 static __failure_type _S_test(...);
2337 template<typename _MemPtr, typename _Arg>
2338 struct __result_of_memobj_ref
2339 : private __result_of_memobj_ref_impl
2341 typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2344 // [func.require] paragraph 1 bullet 4:
2345 struct __result_of_memobj_deref_impl
2347 template<typename _Fp, typename _Tp1>
2348 static __result_of_success<decltype(
2349 (*std::declval<_Tp1>()).*std::declval<_Fp>()
2350 ), __invoke_memobj_deref> _S_test(int);
2352 template<typename, typename>
2353 static __failure_type _S_test(...);
2356 template<typename _MemPtr, typename _Arg>
2357 struct __result_of_memobj_deref
2358 : private __result_of_memobj_deref_impl
2360 typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2363 template<typename _MemPtr, typename _Arg>
2364 struct __result_of_memobj;
2366 template<typename _Res, typename _Class, typename _Arg>
2367 struct __result_of_memobj<_Res _Class::*, _Arg>
2369 typedef typename remove_cv<typename remove_reference<
2370 _Arg>::type>::type _Argval;
2371 typedef _Res _Class::* _MemPtr;
2372 typedef typename conditional<__or_<is_same<_Argval, _Class>,
2373 is_base_of<_Class, _Argval>>::value,
2374 __result_of_memobj_ref<_MemPtr, _Arg>,
2375 __result_of_memobj_deref<_MemPtr, _Arg>
2379 template<typename _MemPtr, typename _Arg, typename... _Args>
2380 struct __result_of_memfun;
2382 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2383 struct __result_of_memfun<_Res _Class::*, _Arg, _Args...>
2385 typedef typename remove_cv<typename remove_reference<
2386 _Arg>::type>::type _Argval;
2387 typedef _Res _Class::* _MemPtr;
2388 typedef typename conditional<__or_<is_same<_Argval, _Class>,
2389 is_base_of<_Class, _Argval>>::value,
2390 __result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
2391 __result_of_memfun_deref<_MemPtr, _Arg, _Args...>
2395 // _GLIBCXX_RESOLVE_LIB_DEFECTS
2396 // 2219. INVOKE-ing a pointer to member with a reference_wrapper
2397 // as the object expression
2399 template<typename _Res, typename _Class, typename _Arg>
2400 struct __result_of_memobj<_Res _Class::*, reference_wrapper<_Arg>>
2401 : __result_of_memobj_ref<_Res _Class::*, _Arg&>
2404 template<typename _Res, typename _Class, typename _Arg>
2405 struct __result_of_memobj<_Res _Class::*, reference_wrapper<_Arg>&>
2406 : __result_of_memobj_ref<_Res _Class::*, _Arg&>
2409 template<typename _Res, typename _Class, typename _Arg>
2410 struct __result_of_memobj<_Res _Class::*, const reference_wrapper<_Arg>&>
2411 : __result_of_memobj_ref<_Res _Class::*, _Arg&>
2414 template<typename _Res, typename _Class, typename _Arg>
2415 struct __result_of_memobj<_Res _Class::*, reference_wrapper<_Arg>&&>
2416 : __result_of_memobj_ref<_Res _Class::*, _Arg&>
2419 template<typename _Res, typename _Class, typename _Arg>
2420 struct __result_of_memobj<_Res _Class::*, const reference_wrapper<_Arg>&&>
2421 : __result_of_memobj_ref<_Res _Class::*, _Arg&>
2424 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2425 struct __result_of_memfun<_Res _Class::*, reference_wrapper<_Arg>, _Args...>
2426 : __result_of_memfun_ref<_Res _Class::*, _Arg&, _Args...>
2429 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2430 struct __result_of_memfun<_Res _Class::*, reference_wrapper<_Arg>&,
2432 : __result_of_memfun_ref<_Res _Class::*, _Arg&, _Args...>
2435 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2436 struct __result_of_memfun<_Res _Class::*, const reference_wrapper<_Arg>&,
2438 : __result_of_memfun_ref<_Res _Class::*, _Arg&, _Args...>
2441 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2442 struct __result_of_memfun<_Res _Class::*, reference_wrapper<_Arg>&&,
2444 : __result_of_memfun_ref<_Res _Class::*, _Arg&, _Args...>
2447 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2448 struct __result_of_memfun<_Res _Class::*, const reference_wrapper<_Arg>&&,
2450 : __result_of_memfun_ref<_Res _Class::*, _Arg&, _Args...>
2453 template<bool, bool, typename _Functor, typename... _ArgTypes>
2454 struct __result_of_impl
2456 typedef __failure_type type;
2459 template<typename _MemPtr, typename _Arg>
2460 struct __result_of_impl<true, false, _MemPtr, _Arg>
2461 : public __result_of_memobj<typename decay<_MemPtr>::type, _Arg>
2464 template<typename _MemPtr, typename _Arg, typename... _Args>
2465 struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
2466 : public __result_of_memfun<typename decay<_MemPtr>::type, _Arg, _Args...>
2469 // [func.require] paragraph 1 bullet 5:
2470 struct __result_of_other_impl
2472 template<typename _Fn, typename... _Args>
2473 static __result_of_success<decltype(
2474 std::declval<_Fn>()(std::declval<_Args>()...)
2475 ), __invoke_other> _S_test(int);
2477 template<typename...>
2478 static __failure_type _S_test(...);
2481 template<typename _Functor, typename... _ArgTypes>
2482 struct __result_of_impl<false, false, _Functor, _ArgTypes...>
2483 : private __result_of_other_impl
2485 typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type;
2488 template<typename _Functor, typename... _ArgTypes>
2489 struct result_of<_Functor(_ArgTypes...)>
2490 : public __result_of_impl<
2491 is_member_object_pointer<
2492 typename remove_reference<_Functor>::type
2494 is_member_function_pointer<
2495 typename remove_reference<_Functor>::type
2497 _Functor, _ArgTypes...
2501 #if __cplusplus > 201103L
2502 /// Alias template for aligned_storage
2503 template<size_t _Len, size_t _Align =
2504 __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2505 using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
2507 template <size_t _Len, typename... _Types>
2508 using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
2510 /// Alias template for decay
2511 template<typename _Tp>
2512 using decay_t = typename decay<_Tp>::type;
2514 /// Alias template for enable_if
2515 template<bool _Cond, typename _Tp = void>
2516 using enable_if_t = typename enable_if<_Cond, _Tp>::type;
2518 /// Alias template for conditional
2519 template<bool _Cond, typename _Iftrue, typename _Iffalse>
2520 using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
2522 /// Alias template for common_type
2523 template<typename... _Tp>
2524 using common_type_t = typename common_type<_Tp...>::type;
2526 /// Alias template for underlying_type
2527 template<typename _Tp>
2528 using underlying_type_t = typename underlying_type<_Tp>::type;
2530 /// Alias template for result_of
2531 template<typename _Tp>
2532 using result_of_t = typename result_of<_Tp>::type;
2535 template<typename...> using __void_t = void;
2537 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
2538 #define __cpp_lib_void_t 201411
2539 /// A metafunction that always yields void, used for detecting valid types.
2540 template<typename...> using void_t = void;
2543 /// Implementation of the detection idiom (negative case).
2544 template<typename _Default, typename _AlwaysVoid,
2545 template<typename...> class _Op, typename... _Args>
2548 using value_t = false_type;
2549 using type = _Default;
2552 /// Implementation of the detection idiom (positive case).
2553 template<typename _Default, template<typename...> class _Op,
2555 struct __detector<_Default, __void_t<_Op<_Args...>>, _Op, _Args...>
2557 using value_t = true_type;
2558 using type = _Op<_Args...>;
2561 // Detect whether _Op<_Args...> is a valid type, use _Default if not.
2562 template<typename _Default, template<typename...> class _Op,
2564 using __detected_or = __detector<_Default, void, _Op, _Args...>;
2566 // _Op<_Args...> if that is a valid type, otherwise _Default.
2567 template<typename _Default, template<typename...> class _Op,
2569 using __detected_or_t
2570 = typename __detected_or<_Default, _Op, _Args...>::type;
2572 // _Op<_Args...> if that is a valid type, otherwise _Default<_Args...>.
2573 template<template<typename...> class _Default,
2574 template<typename...> class _Op, typename... _Args>
2575 using __detected_or_t_ =
2576 __detected_or_t<_Default<_Args...>, _Op, _Args...>;
2578 /// @} group metaprogramming
2581 * Use SFINAE to determine if the type _Tp has a publicly-accessible
2582 * member type _NTYPE.
2584 #define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
2585 template<typename _Tp, typename = __void_t<>> \
2586 struct __has_##_NTYPE \
2589 template<typename _Tp> \
2590 struct __has_##_NTYPE<_Tp, __void_t<typename _Tp::_NTYPE>> \
2594 template <typename _Tp>
2595 struct __is_swappable;
2597 template <typename _Tp>
2598 struct __is_nothrow_swappable;
2600 template<typename _Tp>
2602 typename enable_if<__and_<is_move_constructible<_Tp>,
2603 is_move_assignable<_Tp>>::value>::type
2605 noexcept(__and_<is_nothrow_move_constructible<_Tp>,
2606 is_nothrow_move_assignable<_Tp>>::value);
2608 template<typename _Tp, size_t _Nm>
2610 typename enable_if<__is_swappable<_Tp>::value>::type
2611 swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
2612 noexcept(__is_nothrow_swappable<_Tp>::value);
2614 namespace __swappable_details {
2617 struct __do_is_swappable_impl
2619 template<typename _Tp, typename
2620 = decltype(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))>
2621 static true_type __test(int);
2624 static false_type __test(...);
2627 struct __do_is_nothrow_swappable_impl
2629 template<typename _Tp>
2630 static __bool_constant<
2631 noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))
2635 static false_type __test(...);
2640 template<typename _Tp>
2641 struct __is_swappable_impl
2642 : public __swappable_details::__do_is_swappable_impl
2644 typedef decltype(__test<_Tp>(0)) type;
2647 template<typename _Tp>
2648 struct __is_nothrow_swappable_impl
2649 : public __swappable_details::__do_is_nothrow_swappable_impl
2651 typedef decltype(__test<_Tp>(0)) type;
2654 template<typename _Tp>
2655 struct __is_swappable
2656 : public __is_swappable_impl<_Tp>::type
2659 template<typename _Tp>
2660 struct __is_nothrow_swappable
2661 : public __is_nothrow_swappable_impl<_Tp>::type
2664 _GLIBCXX_END_NAMESPACE_VERSION
2669 #endif // _GLIBCXX_TYPE_TRAITS