1 // C++11 <type_traits> -*- C++ -*-
3 // Copyright (C) 2007-2021 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 namespace std _GLIBCXX_VISIBILITY(default)
42 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44 template<typename... _Elements>
47 template<typename _Tp>
48 class reference_wrapper;
51 * @defgroup metaprogramming Metaprogramming
54 * Template utilities for compile-time introspection and modification,
55 * including type classification traits, type property inspection traits
56 * and type transformation traits.
64 template<typename _Tp, _Tp __v>
65 struct integral_constant
67 static constexpr _Tp value = __v;
68 typedef _Tp value_type;
69 typedef integral_constant<_Tp, __v> type;
70 constexpr operator value_type() const noexcept { return value; }
71 #if __cplusplus > 201103L
73 #define __cpp_lib_integral_constant_callable 201304
75 constexpr value_type operator()() const noexcept { return value; }
79 template<typename _Tp, _Tp __v>
80 constexpr _Tp integral_constant<_Tp, __v>::value;
82 /// The type used as a compile-time boolean with true value.
83 using true_type = integral_constant<bool, true>;
85 /// The type used as a compile-time boolean with false value.
86 using false_type = integral_constant<bool, false>;
88 /// @cond undocumented
89 /// bool_constant for C++11
91 using __bool_constant = integral_constant<bool, __v>;
94 #if __cplusplus >= 201703L
95 # define __cpp_lib_bool_constant 201505
96 /// Alias template for compile-time boolean constant types.
99 using bool_constant = integral_constant<bool, __v>;
102 // Metaprogramming helper types.
104 template<bool, typename, typename>
107 /// @cond undocumented
108 template <typename _Type>
109 struct __type_identity
110 { using type = _Type; };
112 template<typename _Tp>
113 using __type_identity_t = typename __type_identity<_Tp>::type;
115 template<typename...>
123 template<typename _B1>
128 template<typename _B1, typename _B2>
129 struct __or_<_B1, _B2>
130 : public conditional<_B1::value, _B1, _B2>::type
133 template<typename _B1, typename _B2, typename _B3, typename... _Bn>
134 struct __or_<_B1, _B2, _B3, _Bn...>
135 : public conditional<_B1::value, _B1, __or_<_B2, _B3, _Bn...>>::type
138 template<typename...>
146 template<typename _B1>
151 template<typename _B1, typename _B2>
152 struct __and_<_B1, _B2>
153 : public conditional<_B1::value, _B2, _B1>::type
156 template<typename _B1, typename _B2, typename _B3, typename... _Bn>
157 struct __and_<_B1, _B2, _B3, _Bn...>
158 : public conditional<_B1::value, __and_<_B2, _B3, _Bn...>, _B1>::type
161 template<typename _Pp>
163 : public __bool_constant<!bool(_Pp::value)>
167 #if __cplusplus >= 201703L
169 /// @cond undocumented
170 template<typename... _Bn>
171 inline constexpr bool __or_v = __or_<_Bn...>::value;
172 template<typename... _Bn>
173 inline constexpr bool __and_v = __and_<_Bn...>::value;
176 #define __cpp_lib_logical_traits 201510
178 template<typename... _Bn>
183 template<typename... _Bn>
188 template<typename _Pp>
193 /** @ingroup variable_templates
196 template<typename... _Bn>
197 inline constexpr bool conjunction_v = conjunction<_Bn...>::value;
199 template<typename... _Bn>
200 inline constexpr bool disjunction_v = disjunction<_Bn...>::value;
202 template<typename _Pp>
203 inline constexpr bool negation_v = negation<_Pp>::value;
208 // Forward declarations
220 /// @cond undocumented
222 struct __is_array_unknown_bounds;
224 // Helper functions that return false_type for incomplete classes,
225 // incomplete unions and arrays of known bound from those.
227 template <typename _Tp, size_t = sizeof(_Tp)>
228 constexpr true_type __is_complete_or_unbounded(__type_identity<_Tp>)
231 template <typename _TypeIdentity,
232 typename _NestedType = typename _TypeIdentity::type>
233 constexpr typename __or_<
234 is_reference<_NestedType>,
235 is_function<_NestedType>,
236 is_void<_NestedType>,
237 __is_array_unknown_bounds<_NestedType>
238 >::type __is_complete_or_unbounded(_TypeIdentity)
241 // For several sfinae-friendly trait implementations we transport both the
242 // result information (as the member type) and the failure information (no
243 // member type). This is very similar to std::enable_if, but we cannot use
244 // them, because we need to derive from them as an implementation detail.
246 template<typename _Tp>
247 struct __success_type
248 { typedef _Tp type; };
250 struct __failure_type
253 // __remove_cv_t (std::remove_cv_t for C++11).
254 template<typename _Tp>
255 using __remove_cv_t = typename remove_cv<_Tp>::type;
257 // Primary type categories.
260 struct __is_void_helper
261 : public false_type { };
264 struct __is_void_helper<void>
265 : public true_type { };
269 template<typename _Tp>
271 : public __is_void_helper<__remove_cv_t<_Tp>>::type
274 /// @cond undocumented
276 struct __is_integral_helper
277 : public false_type { };
280 struct __is_integral_helper<bool>
281 : public true_type { };
284 struct __is_integral_helper<char>
285 : public true_type { };
288 struct __is_integral_helper<signed char>
289 : public true_type { };
292 struct __is_integral_helper<unsigned char>
293 : public true_type { };
295 // We want is_integral<wchar_t> to be true (and make_signed/unsigned to work)
296 // even when libc doesn't provide working <wchar.h> and related functions,
297 // so check __WCHAR_TYPE__ instead of _GLIBCXX_USE_WCHAR_T.
298 #ifdef __WCHAR_TYPE__
300 struct __is_integral_helper<wchar_t>
301 : public true_type { };
304 #ifdef _GLIBCXX_USE_CHAR8_T
306 struct __is_integral_helper<char8_t>
307 : public true_type { };
311 struct __is_integral_helper<char16_t>
312 : public true_type { };
315 struct __is_integral_helper<char32_t>
316 : public true_type { };
319 struct __is_integral_helper<short>
320 : public true_type { };
323 struct __is_integral_helper<unsigned short>
324 : public true_type { };
327 struct __is_integral_helper<int>
328 : public true_type { };
331 struct __is_integral_helper<unsigned int>
332 : public true_type { };
335 struct __is_integral_helper<long>
336 : public true_type { };
339 struct __is_integral_helper<unsigned long>
340 : public true_type { };
343 struct __is_integral_helper<long long>
344 : public true_type { };
347 struct __is_integral_helper<unsigned long long>
348 : public true_type { };
350 // Conditionalizing on __STRICT_ANSI__ here will break any port that
351 // uses one of these types for size_t.
352 #if defined(__GLIBCXX_TYPE_INT_N_0)
354 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_0>
355 : public true_type { };
358 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_0>
359 : public true_type { };
361 #if defined(__GLIBCXX_TYPE_INT_N_1)
363 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_1>
364 : public true_type { };
367 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_1>
368 : public true_type { };
370 #if defined(__GLIBCXX_TYPE_INT_N_2)
372 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_2>
373 : public true_type { };
376 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_2>
377 : public true_type { };
379 #if defined(__GLIBCXX_TYPE_INT_N_3)
381 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_3>
382 : public true_type { };
385 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_3>
386 : public true_type { };
391 template<typename _Tp>
393 : public __is_integral_helper<__remove_cv_t<_Tp>>::type
396 /// @cond undocumented
398 struct __is_floating_point_helper
399 : public false_type { };
402 struct __is_floating_point_helper<float>
403 : public true_type { };
406 struct __is_floating_point_helper<double>
407 : public true_type { };
410 struct __is_floating_point_helper<long double>
411 : public true_type { };
413 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
415 struct __is_floating_point_helper<__float128>
416 : public true_type { };
420 /// is_floating_point
421 template<typename _Tp>
422 struct is_floating_point
423 : public __is_floating_point_helper<__remove_cv_t<_Tp>>::type
429 : public false_type { };
431 template<typename _Tp, std::size_t _Size>
432 struct is_array<_Tp[_Size]>
433 : public true_type { };
435 template<typename _Tp>
436 struct is_array<_Tp[]>
437 : public true_type { };
440 struct __is_pointer_helper
441 : public false_type { };
443 template<typename _Tp>
444 struct __is_pointer_helper<_Tp*>
445 : public true_type { };
448 template<typename _Tp>
450 : public __is_pointer_helper<__remove_cv_t<_Tp>>::type
453 /// is_lvalue_reference
455 struct is_lvalue_reference
456 : public false_type { };
458 template<typename _Tp>
459 struct is_lvalue_reference<_Tp&>
460 : public true_type { };
462 /// is_rvalue_reference
464 struct is_rvalue_reference
465 : public false_type { };
467 template<typename _Tp>
468 struct is_rvalue_reference<_Tp&&>
469 : public true_type { };
472 struct __is_member_object_pointer_helper
473 : public false_type { };
475 template<typename _Tp, typename _Cp>
476 struct __is_member_object_pointer_helper<_Tp _Cp::*>
477 : public __not_<is_function<_Tp>>::type { };
479 /// is_member_object_pointer
480 template<typename _Tp>
481 struct is_member_object_pointer
482 : public __is_member_object_pointer_helper<__remove_cv_t<_Tp>>::type
486 struct __is_member_function_pointer_helper
487 : public false_type { };
489 template<typename _Tp, typename _Cp>
490 struct __is_member_function_pointer_helper<_Tp _Cp::*>
491 : public is_function<_Tp>::type { };
493 /// is_member_function_pointer
494 template<typename _Tp>
495 struct is_member_function_pointer
496 : public __is_member_function_pointer_helper<__remove_cv_t<_Tp>>::type
500 template<typename _Tp>
502 : public integral_constant<bool, __is_enum(_Tp)>
506 template<typename _Tp>
508 : public integral_constant<bool, __is_union(_Tp)>
512 template<typename _Tp>
514 : public integral_constant<bool, __is_class(_Tp)>
518 template<typename _Tp>
520 : public __bool_constant<!is_const<const _Tp>::value> { };
522 template<typename _Tp>
523 struct is_function<_Tp&>
524 : public false_type { };
526 template<typename _Tp>
527 struct is_function<_Tp&&>
528 : public false_type { };
530 #define __cpp_lib_is_null_pointer 201309
533 struct __is_null_pointer_helper
534 : public false_type { };
537 struct __is_null_pointer_helper<std::nullptr_t>
538 : public true_type { };
540 /// is_null_pointer (LWG 2247).
541 template<typename _Tp>
542 struct is_null_pointer
543 : public __is_null_pointer_helper<__remove_cv_t<_Tp>>::type
546 /// __is_nullptr_t (deprecated extension).
547 /// @deprecated Use `is_null_pointer` instead.
548 template<typename _Tp>
549 struct __is_nullptr_t
550 : public is_null_pointer<_Tp>
551 { } _GLIBCXX_DEPRECATED_SUGGEST("std::is_null_pointer");
553 // Composite type categories.
556 template<typename _Tp>
558 : public __or_<is_lvalue_reference<_Tp>,
559 is_rvalue_reference<_Tp>>::type
563 template<typename _Tp>
565 : public __or_<is_integral<_Tp>, is_floating_point<_Tp>>::type
569 template<typename _Tp>
570 struct is_fundamental
571 : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
572 is_null_pointer<_Tp>>::type
576 template<typename _Tp>
578 : public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
583 struct is_member_pointer;
586 template<typename _Tp>
588 : public __or_<is_arithmetic<_Tp>, is_enum<_Tp>, is_pointer<_Tp>,
589 is_member_pointer<_Tp>, is_null_pointer<_Tp>>::type
593 template<typename _Tp>
595 : public __not_<is_fundamental<_Tp>>::type { };
597 /// @cond undocumented
598 template<typename _Tp>
599 struct __is_member_pointer_helper
600 : public false_type { };
602 template<typename _Tp, typename _Cp>
603 struct __is_member_pointer_helper<_Tp _Cp::*>
604 : public true_type { };
607 /// is_member_pointer
608 template<typename _Tp>
609 struct is_member_pointer
610 : public __is_member_pointer_helper<__remove_cv_t<_Tp>>::type
613 template<typename, typename>
616 /// @cond undocumented
617 template<typename _Tp, typename... _Types>
618 using __is_one_of = __or_<is_same<_Tp, _Types>...>;
620 // Check if a type is one of the signed integer types.
621 template<typename _Tp>
622 using __is_signed_integer = __is_one_of<__remove_cv_t<_Tp>,
623 signed char, signed short, signed int, signed long,
625 #if defined(__GLIBCXX_TYPE_INT_N_0)
626 , signed __GLIBCXX_TYPE_INT_N_0
628 #if defined(__GLIBCXX_TYPE_INT_N_1)
629 , signed __GLIBCXX_TYPE_INT_N_1
631 #if defined(__GLIBCXX_TYPE_INT_N_2)
632 , signed __GLIBCXX_TYPE_INT_N_2
634 #if defined(__GLIBCXX_TYPE_INT_N_3)
635 , signed __GLIBCXX_TYPE_INT_N_3
639 // Check if a type is one of the unsigned integer types.
640 template<typename _Tp>
641 using __is_unsigned_integer = __is_one_of<__remove_cv_t<_Tp>,
642 unsigned char, unsigned short, unsigned int, unsigned long,
644 #if defined(__GLIBCXX_TYPE_INT_N_0)
645 , unsigned __GLIBCXX_TYPE_INT_N_0
647 #if defined(__GLIBCXX_TYPE_INT_N_1)
648 , unsigned __GLIBCXX_TYPE_INT_N_1
650 #if defined(__GLIBCXX_TYPE_INT_N_2)
651 , unsigned __GLIBCXX_TYPE_INT_N_2
653 #if defined(__GLIBCXX_TYPE_INT_N_3)
654 , unsigned __GLIBCXX_TYPE_INT_N_3
658 // Check if a type is one of the signed or unsigned integer types.
659 template<typename _Tp>
660 using __is_standard_integer
661 = __or_<__is_signed_integer<_Tp>, __is_unsigned_integer<_Tp>>;
663 // __void_t (std::void_t for C++11)
664 template<typename...> using __void_t = void;
666 // Utility to detect referenceable types ([defns.referenceable]).
668 template<typename _Tp, typename = void>
669 struct __is_referenceable
673 template<typename _Tp>
674 struct __is_referenceable<_Tp, __void_t<_Tp&>>
684 : public false_type { };
686 template<typename _Tp>
687 struct is_const<_Tp const>
688 : public true_type { };
693 : public false_type { };
695 template<typename _Tp>
696 struct is_volatile<_Tp volatile>
697 : public true_type { };
700 template<typename _Tp>
702 : public integral_constant<bool, __is_trivial(_Tp)>
704 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
705 "template argument must be a complete class or an unbounded array");
708 /// is_trivially_copyable
709 template<typename _Tp>
710 struct is_trivially_copyable
711 : public integral_constant<bool, __is_trivially_copyable(_Tp)>
713 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
714 "template argument must be a complete class or an unbounded array");
717 /// is_standard_layout
718 template<typename _Tp>
719 struct is_standard_layout
720 : public integral_constant<bool, __is_standard_layout(_Tp)>
722 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
723 "template argument must be a complete class or an unbounded array");
726 /** is_pod (deprecated in C++20)
727 * @deprecated Use `is_standard_layout && is_trivial` instead.
729 // Could use is_standard_layout && is_trivial instead of the builtin.
730 template<typename _Tp>
732 _GLIBCXX20_DEPRECATED("use is_standard_layout && is_trivial instead")
734 : public integral_constant<bool, __is_pod(_Tp)>
736 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
737 "template argument must be a complete class or an unbounded array");
741 * @deprecated Deprecated in C++20. The idea of a literal type isn't useful.
743 template<typename _Tp>
745 _GLIBCXX17_DEPRECATED
747 : public integral_constant<bool, __is_literal_type(_Tp)>
749 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
750 "template argument must be a complete class or an unbounded array");
754 template<typename _Tp>
756 : public integral_constant<bool, __is_empty(_Tp)>
760 template<typename _Tp>
761 struct is_polymorphic
762 : public integral_constant<bool, __is_polymorphic(_Tp)>
765 #if __cplusplus >= 201402L
766 #define __cpp_lib_is_final 201402L
769 template<typename _Tp>
771 : public integral_constant<bool, __is_final(_Tp)>
776 template<typename _Tp>
778 : public integral_constant<bool, __is_abstract(_Tp)>
781 /// @cond undocumented
782 template<typename _Tp,
783 bool = is_arithmetic<_Tp>::value>
784 struct __is_signed_helper
785 : public false_type { };
787 template<typename _Tp>
788 struct __is_signed_helper<_Tp, true>
789 : public integral_constant<bool, _Tp(-1) < _Tp(0)>
794 template<typename _Tp>
796 : public __is_signed_helper<_Tp>::type
800 template<typename _Tp>
802 : public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>
805 /// @cond undocumented
806 template<typename _Tp, typename _Up = _Tp&&>
810 template<typename _Tp>
815 template<typename _Tp>
816 auto declval() noexcept -> decltype(__declval<_Tp>(0));
818 template<typename, unsigned = 0>
822 struct remove_all_extents;
824 /// @cond undocumented
825 template<typename _Tp>
826 struct __is_array_known_bounds
827 : public integral_constant<bool, (extent<_Tp>::value > 0)>
830 template<typename _Tp>
831 struct __is_array_unknown_bounds
832 : public __and_<is_array<_Tp>, __not_<extent<_Tp>>>
835 // Destructible and constructible type properties.
837 // In N3290 is_destructible does not say anything about function
838 // types and abstract types, see LWG 2049. This implementation
839 // describes function types as non-destructible and all complete
840 // object types as destructible, iff the explicit destructor
841 // call expression is wellformed.
842 struct __do_is_destructible_impl
844 template<typename _Tp, typename = decltype(declval<_Tp&>().~_Tp())>
845 static true_type __test(int);
848 static false_type __test(...);
851 template<typename _Tp>
852 struct __is_destructible_impl
853 : public __do_is_destructible_impl
855 typedef decltype(__test<_Tp>(0)) type;
858 template<typename _Tp,
859 bool = __or_<is_void<_Tp>,
860 __is_array_unknown_bounds<_Tp>,
861 is_function<_Tp>>::value,
862 bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
863 struct __is_destructible_safe;
865 template<typename _Tp>
866 struct __is_destructible_safe<_Tp, false, false>
867 : public __is_destructible_impl<typename
868 remove_all_extents<_Tp>::type>::type
871 template<typename _Tp>
872 struct __is_destructible_safe<_Tp, true, false>
873 : public false_type { };
875 template<typename _Tp>
876 struct __is_destructible_safe<_Tp, false, true>
877 : public true_type { };
881 template<typename _Tp>
882 struct is_destructible
883 : public __is_destructible_safe<_Tp>::type
885 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
886 "template argument must be a complete class or an unbounded array");
889 /// @cond undocumented
891 // is_nothrow_destructible requires that is_destructible is
892 // satisfied as well. We realize that by mimicing the
893 // implementation of is_destructible but refer to noexcept(expr)
894 // instead of decltype(expr).
895 struct __do_is_nt_destructible_impl
897 template<typename _Tp>
898 static __bool_constant<noexcept(declval<_Tp&>().~_Tp())>
902 static false_type __test(...);
905 template<typename _Tp>
906 struct __is_nt_destructible_impl
907 : public __do_is_nt_destructible_impl
909 typedef decltype(__test<_Tp>(0)) type;
912 template<typename _Tp,
913 bool = __or_<is_void<_Tp>,
914 __is_array_unknown_bounds<_Tp>,
915 is_function<_Tp>>::value,
916 bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
917 struct __is_nt_destructible_safe;
919 template<typename _Tp>
920 struct __is_nt_destructible_safe<_Tp, false, false>
921 : public __is_nt_destructible_impl<typename
922 remove_all_extents<_Tp>::type>::type
925 template<typename _Tp>
926 struct __is_nt_destructible_safe<_Tp, true, false>
927 : public false_type { };
929 template<typename _Tp>
930 struct __is_nt_destructible_safe<_Tp, false, true>
931 : public true_type { };
934 /// is_nothrow_destructible
935 template<typename _Tp>
936 struct is_nothrow_destructible
937 : public __is_nt_destructible_safe<_Tp>::type
939 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
940 "template argument must be a complete class or an unbounded array");
943 /// @cond undocumented
944 template<typename _Tp, typename... _Args>
945 struct __is_constructible_impl
946 : public __bool_constant<__is_constructible(_Tp, _Args...)>
951 template<typename _Tp, typename... _Args>
952 struct is_constructible
953 : public __is_constructible_impl<_Tp, _Args...>
955 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
956 "template argument must be a complete class or an unbounded array");
959 /// is_default_constructible
960 template<typename _Tp>
961 struct is_default_constructible
962 : public __is_constructible_impl<_Tp>::type
964 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
965 "template argument must be a complete class or an unbounded array");
968 /// @cond undocumented
969 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
970 struct __is_copy_constructible_impl;
972 template<typename _Tp>
973 struct __is_copy_constructible_impl<_Tp, false>
974 : public false_type { };
976 template<typename _Tp>
977 struct __is_copy_constructible_impl<_Tp, true>
978 : public __is_constructible_impl<_Tp, const _Tp&>
982 /// is_copy_constructible
983 template<typename _Tp>
984 struct is_copy_constructible
985 : public __is_copy_constructible_impl<_Tp>
987 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
988 "template argument must be a complete class or an unbounded array");
991 /// @cond undocumented
992 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
993 struct __is_move_constructible_impl;
995 template<typename _Tp>
996 struct __is_move_constructible_impl<_Tp, false>
997 : public false_type { };
999 template<typename _Tp>
1000 struct __is_move_constructible_impl<_Tp, true>
1001 : public __is_constructible_impl<_Tp, _Tp&&>
1005 /// is_move_constructible
1006 template<typename _Tp>
1007 struct is_move_constructible
1008 : public __is_move_constructible_impl<_Tp>
1010 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1011 "template argument must be a complete class or an unbounded array");
1014 /// @cond undocumented
1015 template<typename _Tp, typename... _Args>
1016 using __is_nothrow_constructible_impl
1017 = __bool_constant<__is_nothrow_constructible(_Tp, _Args...)>;
1020 /// is_nothrow_constructible
1021 template<typename _Tp, typename... _Args>
1022 struct is_nothrow_constructible
1023 : public __is_nothrow_constructible_impl<_Tp, _Args...>::type
1025 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1026 "template argument must be a complete class or an unbounded array");
1029 /// is_nothrow_default_constructible
1030 template<typename _Tp>
1031 struct is_nothrow_default_constructible
1032 : public __bool_constant<__is_nothrow_constructible(_Tp)>
1034 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1035 "template argument must be a complete class or an unbounded array");
1038 /// @cond undocumented
1039 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1040 struct __is_nothrow_copy_constructible_impl;
1042 template<typename _Tp>
1043 struct __is_nothrow_copy_constructible_impl<_Tp, false>
1044 : public false_type { };
1046 template<typename _Tp>
1047 struct __is_nothrow_copy_constructible_impl<_Tp, true>
1048 : public __is_nothrow_constructible_impl<_Tp, const _Tp&>
1052 /// is_nothrow_copy_constructible
1053 template<typename _Tp>
1054 struct is_nothrow_copy_constructible
1055 : public __is_nothrow_copy_constructible_impl<_Tp>::type
1057 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1058 "template argument must be a complete class or an unbounded array");
1061 /// @cond undocumented
1062 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1063 struct __is_nothrow_move_constructible_impl;
1065 template<typename _Tp>
1066 struct __is_nothrow_move_constructible_impl<_Tp, false>
1067 : public false_type { };
1069 template<typename _Tp>
1070 struct __is_nothrow_move_constructible_impl<_Tp, true>
1071 : public __is_nothrow_constructible_impl<_Tp, _Tp&&>
1075 /// is_nothrow_move_constructible
1076 template<typename _Tp>
1077 struct is_nothrow_move_constructible
1078 : public __is_nothrow_move_constructible_impl<_Tp>::type
1080 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1081 "template argument must be a complete class or an unbounded array");
1085 template<typename _Tp, typename _Up>
1086 struct is_assignable
1087 : public __bool_constant<__is_assignable(_Tp, _Up)>
1089 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1090 "template argument must be a complete class or an unbounded array");
1093 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1094 struct __is_copy_assignable_impl;
1096 template<typename _Tp>
1097 struct __is_copy_assignable_impl<_Tp, false>
1098 : public false_type { };
1100 template<typename _Tp>
1101 struct __is_copy_assignable_impl<_Tp, true>
1102 : public __bool_constant<__is_assignable(_Tp&, const _Tp&)>
1105 /// is_copy_assignable
1106 template<typename _Tp>
1107 struct is_copy_assignable
1108 : public __is_copy_assignable_impl<_Tp>::type
1110 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1111 "template argument must be a complete class or an unbounded array");
1114 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1115 struct __is_move_assignable_impl;
1117 template<typename _Tp>
1118 struct __is_move_assignable_impl<_Tp, false>
1119 : public false_type { };
1121 template<typename _Tp>
1122 struct __is_move_assignable_impl<_Tp, true>
1123 : public __bool_constant<__is_assignable(_Tp&, _Tp&&)>
1126 /// is_move_assignable
1127 template<typename _Tp>
1128 struct is_move_assignable
1129 : public __is_move_assignable_impl<_Tp>::type
1131 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1132 "template argument must be a complete class or an unbounded array");
1135 template<typename _Tp, typename _Up>
1136 using __is_nothrow_assignable_impl
1137 = __bool_constant<__is_nothrow_assignable(_Tp, _Up)>;
1139 /// is_nothrow_assignable
1140 template<typename _Tp, typename _Up>
1141 struct is_nothrow_assignable
1142 : public __is_nothrow_assignable_impl<_Tp, _Up>
1144 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1145 "template argument must be a complete class or an unbounded array");
1148 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1149 struct __is_nt_copy_assignable_impl;
1151 template<typename _Tp>
1152 struct __is_nt_copy_assignable_impl<_Tp, false>
1153 : public false_type { };
1155 template<typename _Tp>
1156 struct __is_nt_copy_assignable_impl<_Tp, true>
1157 : public __is_nothrow_assignable_impl<_Tp&, const _Tp&>
1160 /// is_nothrow_copy_assignable
1161 template<typename _Tp>
1162 struct is_nothrow_copy_assignable
1163 : public __is_nt_copy_assignable_impl<_Tp>
1165 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1166 "template argument must be a complete class or an unbounded array");
1169 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1170 struct __is_nt_move_assignable_impl;
1172 template<typename _Tp>
1173 struct __is_nt_move_assignable_impl<_Tp, false>
1174 : public false_type { };
1176 template<typename _Tp>
1177 struct __is_nt_move_assignable_impl<_Tp, true>
1178 : public __is_nothrow_assignable_impl<_Tp&, _Tp&&>
1181 /// is_nothrow_move_assignable
1182 template<typename _Tp>
1183 struct is_nothrow_move_assignable
1184 : public __is_nt_move_assignable_impl<_Tp>
1186 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1187 "template argument must be a complete class or an unbounded array");
1190 /// is_trivially_constructible
1191 template<typename _Tp, typename... _Args>
1192 struct is_trivially_constructible
1193 : public __bool_constant<__is_trivially_constructible(_Tp, _Args...)>
1195 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1196 "template argument must be a complete class or an unbounded array");
1199 /// is_trivially_default_constructible
1200 template<typename _Tp>
1201 struct is_trivially_default_constructible
1202 : public __bool_constant<__is_trivially_constructible(_Tp)>
1204 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1205 "template argument must be a complete class or an unbounded array");
1208 struct __do_is_implicitly_default_constructible_impl
1210 template <typename _Tp>
1211 static void __helper(const _Tp&);
1213 template <typename _Tp>
1214 static true_type __test(const _Tp&,
1215 decltype(__helper<const _Tp&>({}))* = 0);
1217 static false_type __test(...);
1220 template<typename _Tp>
1221 struct __is_implicitly_default_constructible_impl
1222 : public __do_is_implicitly_default_constructible_impl
1224 typedef decltype(__test(declval<_Tp>())) type;
1227 template<typename _Tp>
1228 struct __is_implicitly_default_constructible_safe
1229 : public __is_implicitly_default_constructible_impl<_Tp>::type
1232 template <typename _Tp>
1233 struct __is_implicitly_default_constructible
1234 : public __and_<__is_constructible_impl<_Tp>,
1235 __is_implicitly_default_constructible_safe<_Tp>>
1238 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1239 struct __is_trivially_copy_constructible_impl;
1241 template<typename _Tp>
1242 struct __is_trivially_copy_constructible_impl<_Tp, false>
1243 : public false_type { };
1245 template<typename _Tp>
1246 struct __is_trivially_copy_constructible_impl<_Tp, true>
1247 : public __and_<__is_copy_constructible_impl<_Tp>,
1248 integral_constant<bool,
1249 __is_trivially_constructible(_Tp, const _Tp&)>>
1252 /// is_trivially_copy_constructible
1253 template<typename _Tp>
1254 struct is_trivially_copy_constructible
1255 : public __is_trivially_copy_constructible_impl<_Tp>
1257 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1258 "template argument must be a complete class or an unbounded array");
1261 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1262 struct __is_trivially_move_constructible_impl;
1264 template<typename _Tp>
1265 struct __is_trivially_move_constructible_impl<_Tp, false>
1266 : public false_type { };
1268 template<typename _Tp>
1269 struct __is_trivially_move_constructible_impl<_Tp, true>
1270 : public __and_<__is_move_constructible_impl<_Tp>,
1271 integral_constant<bool,
1272 __is_trivially_constructible(_Tp, _Tp&&)>>
1275 /// is_trivially_move_constructible
1276 template<typename _Tp>
1277 struct is_trivially_move_constructible
1278 : public __is_trivially_move_constructible_impl<_Tp>
1280 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1281 "template argument must be a complete class or an unbounded array");
1284 /// is_trivially_assignable
1285 template<typename _Tp, typename _Up>
1286 struct is_trivially_assignable
1287 : public __bool_constant<__is_trivially_assignable(_Tp, _Up)>
1289 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1290 "template argument must be a complete class or an unbounded array");
1293 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1294 struct __is_trivially_copy_assignable_impl;
1296 template<typename _Tp>
1297 struct __is_trivially_copy_assignable_impl<_Tp, false>
1298 : public false_type { };
1300 template<typename _Tp>
1301 struct __is_trivially_copy_assignable_impl<_Tp, true>
1302 : public __bool_constant<__is_trivially_assignable(_Tp&, const _Tp&)>
1305 /// is_trivially_copy_assignable
1306 template<typename _Tp>
1307 struct is_trivially_copy_assignable
1308 : public __is_trivially_copy_assignable_impl<_Tp>
1310 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1311 "template argument must be a complete class or an unbounded array");
1314 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1315 struct __is_trivially_move_assignable_impl;
1317 template<typename _Tp>
1318 struct __is_trivially_move_assignable_impl<_Tp, false>
1319 : public false_type { };
1321 template<typename _Tp>
1322 struct __is_trivially_move_assignable_impl<_Tp, true>
1323 : public __bool_constant<__is_trivially_assignable(_Tp&, _Tp&&)>
1326 /// is_trivially_move_assignable
1327 template<typename _Tp>
1328 struct is_trivially_move_assignable
1329 : public __is_trivially_move_assignable_impl<_Tp>
1331 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1332 "template argument must be a complete class or an unbounded array");
1335 /// is_trivially_destructible
1336 template<typename _Tp>
1337 struct is_trivially_destructible
1338 : public __and_<__is_destructible_safe<_Tp>,
1339 __bool_constant<__has_trivial_destructor(_Tp)>>
1341 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1342 "template argument must be a complete class or an unbounded array");
1346 /// has_virtual_destructor
1347 template<typename _Tp>
1348 struct has_virtual_destructor
1349 : public integral_constant<bool, __has_virtual_destructor(_Tp)>
1351 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1352 "template argument must be a complete class or an unbounded array");
1356 // type property queries.
1359 template<typename _Tp>
1361 : public integral_constant<std::size_t, alignof(_Tp)>
1363 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1364 "template argument must be a complete class or an unbounded array");
1370 : public integral_constant<std::size_t, 0> { };
1372 template<typename _Tp, std::size_t _Size>
1373 struct rank<_Tp[_Size]>
1374 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1376 template<typename _Tp>
1378 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1381 template<typename, unsigned _Uint>
1383 : public integral_constant<std::size_t, 0> { };
1385 template<typename _Tp, unsigned _Uint, std::size_t _Size>
1386 struct extent<_Tp[_Size], _Uint>
1387 : public integral_constant<std::size_t,
1388 _Uint == 0 ? _Size : extent<_Tp,
1392 template<typename _Tp, unsigned _Uint>
1393 struct extent<_Tp[], _Uint>
1394 : public integral_constant<std::size_t,
1395 _Uint == 0 ? 0 : extent<_Tp,
1403 template<typename _Tp, typename _Up>
1405 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_SAME
1406 : public integral_constant<bool, __is_same(_Tp, _Up)>
1412 #ifndef _GLIBCXX_HAVE_BUILTIN_IS_SAME
1413 template<typename _Tp>
1414 struct is_same<_Tp, _Tp>
1420 template<typename _Base, typename _Derived>
1422 : public integral_constant<bool, __is_base_of(_Base, _Derived)>
1425 template<typename _From, typename _To,
1426 bool = __or_<is_void<_From>, is_function<_To>,
1427 is_array<_To>>::value>
1428 struct __is_convertible_helper
1430 typedef typename is_void<_To>::type type;
1433 #pragma GCC diagnostic push
1434 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
1435 template<typename _From, typename _To>
1436 class __is_convertible_helper<_From, _To, false>
1438 template<typename _To1>
1439 static void __test_aux(_To1) noexcept;
1441 template<typename _From1, typename _To1,
1442 typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
1446 template<typename, typename>
1451 typedef decltype(__test<_From, _To>(0)) type;
1453 #pragma GCC diagnostic pop
1456 template<typename _From, typename _To>
1457 struct is_convertible
1458 : public __is_convertible_helper<_From, _To>::type
1461 // helper trait for unique_ptr<T[]>, shared_ptr<T[]>, and span<T, N>
1462 template<typename _ToElementType, typename _FromElementType>
1463 using __is_array_convertible
1464 = is_convertible<_FromElementType(*)[], _ToElementType(*)[]>;
1466 template<typename _From, typename _To,
1467 bool = __or_<is_void<_From>, is_function<_To>,
1468 is_array<_To>>::value>
1469 struct __is_nt_convertible_helper
1473 #pragma GCC diagnostic push
1474 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
1475 template<typename _From, typename _To>
1476 class __is_nt_convertible_helper<_From, _To, false>
1478 template<typename _To1>
1479 static void __test_aux(_To1) noexcept;
1481 template<typename _From1, typename _To1>
1483 __bool_constant<noexcept(__test_aux<_To1>(std::declval<_From1>()))>
1486 template<typename, typename>
1491 using type = decltype(__test<_From, _To>(0));
1493 #pragma GCC diagnostic pop
1495 // is_nothrow_convertible for C++11
1496 template<typename _From, typename _To>
1497 struct __is_nothrow_convertible
1498 : public __is_nt_convertible_helper<_From, _To>::type
1501 #if __cplusplus > 201703L
1502 #define __cpp_lib_is_nothrow_convertible 201806L
1503 /// is_nothrow_convertible
1504 template<typename _From, typename _To>
1505 struct is_nothrow_convertible
1506 : public __is_nt_convertible_helper<_From, _To>::type
1509 /// is_nothrow_convertible_v
1510 template<typename _From, typename _To>
1511 inline constexpr bool is_nothrow_convertible_v
1512 = is_nothrow_convertible<_From, _To>::value;
1515 // Const-volatile modifications.
1518 template<typename _Tp>
1520 { typedef _Tp type; };
1522 template<typename _Tp>
1523 struct remove_const<_Tp const>
1524 { typedef _Tp type; };
1527 template<typename _Tp>
1528 struct remove_volatile
1529 { typedef _Tp type; };
1531 template<typename _Tp>
1532 struct remove_volatile<_Tp volatile>
1533 { typedef _Tp type; };
1536 template<typename _Tp>
1538 { using type = _Tp; };
1540 template<typename _Tp>
1541 struct remove_cv<const _Tp>
1542 { using type = _Tp; };
1544 template<typename _Tp>
1545 struct remove_cv<volatile _Tp>
1546 { using type = _Tp; };
1548 template<typename _Tp>
1549 struct remove_cv<const volatile _Tp>
1550 { using type = _Tp; };
1553 template<typename _Tp>
1555 { typedef _Tp const type; };
1558 template<typename _Tp>
1560 { typedef _Tp volatile type; };
1563 template<typename _Tp>
1567 add_const<typename add_volatile<_Tp>::type>::type type;
1570 #if __cplusplus > 201103L
1572 #define __cpp_lib_transformation_trait_aliases 201304
1574 /// Alias template for remove_const
1575 template<typename _Tp>
1576 using remove_const_t = typename remove_const<_Tp>::type;
1578 /// Alias template for remove_volatile
1579 template<typename _Tp>
1580 using remove_volatile_t = typename remove_volatile<_Tp>::type;
1582 /// Alias template for remove_cv
1583 template<typename _Tp>
1584 using remove_cv_t = typename remove_cv<_Tp>::type;
1586 /// Alias template for add_const
1587 template<typename _Tp>
1588 using add_const_t = typename add_const<_Tp>::type;
1590 /// Alias template for add_volatile
1591 template<typename _Tp>
1592 using add_volatile_t = typename add_volatile<_Tp>::type;
1594 /// Alias template for add_cv
1595 template<typename _Tp>
1596 using add_cv_t = typename add_cv<_Tp>::type;
1599 // Reference transformations.
1601 /// remove_reference
1602 template<typename _Tp>
1603 struct remove_reference
1604 { typedef _Tp type; };
1606 template<typename _Tp>
1607 struct remove_reference<_Tp&>
1608 { typedef _Tp type; };
1610 template<typename _Tp>
1611 struct remove_reference<_Tp&&>
1612 { typedef _Tp type; };
1614 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1615 struct __add_lvalue_reference_helper
1616 { typedef _Tp type; };
1618 template<typename _Tp>
1619 struct __add_lvalue_reference_helper<_Tp, true>
1620 { typedef _Tp& type; };
1622 /// add_lvalue_reference
1623 template<typename _Tp>
1624 struct add_lvalue_reference
1625 : public __add_lvalue_reference_helper<_Tp>
1628 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1629 struct __add_rvalue_reference_helper
1630 { typedef _Tp type; };
1632 template<typename _Tp>
1633 struct __add_rvalue_reference_helper<_Tp, true>
1634 { typedef _Tp&& type; };
1636 /// add_rvalue_reference
1637 template<typename _Tp>
1638 struct add_rvalue_reference
1639 : public __add_rvalue_reference_helper<_Tp>
1642 #if __cplusplus > 201103L
1643 /// Alias template for remove_reference
1644 template<typename _Tp>
1645 using remove_reference_t = typename remove_reference<_Tp>::type;
1647 /// Alias template for add_lvalue_reference
1648 template<typename _Tp>
1649 using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
1651 /// Alias template for add_rvalue_reference
1652 template<typename _Tp>
1653 using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
1656 // Sign modifications.
1658 /// @cond undocumented
1660 // Utility for constructing identically cv-qualified types.
1661 template<typename _Unqualified, bool _IsConst, bool _IsVol>
1662 struct __cv_selector;
1664 template<typename _Unqualified>
1665 struct __cv_selector<_Unqualified, false, false>
1666 { typedef _Unqualified __type; };
1668 template<typename _Unqualified>
1669 struct __cv_selector<_Unqualified, false, true>
1670 { typedef volatile _Unqualified __type; };
1672 template<typename _Unqualified>
1673 struct __cv_selector<_Unqualified, true, false>
1674 { typedef const _Unqualified __type; };
1676 template<typename _Unqualified>
1677 struct __cv_selector<_Unqualified, true, true>
1678 { typedef const volatile _Unqualified __type; };
1680 template<typename _Qualified, typename _Unqualified,
1681 bool _IsConst = is_const<_Qualified>::value,
1682 bool _IsVol = is_volatile<_Qualified>::value>
1683 class __match_cv_qualifiers
1685 typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
1688 typedef typename __match::__type __type;
1691 // Utility for finding the unsigned versions of signed integral types.
1692 template<typename _Tp>
1693 struct __make_unsigned
1694 { typedef _Tp __type; };
1697 struct __make_unsigned<char>
1698 { typedef unsigned char __type; };
1701 struct __make_unsigned<signed char>
1702 { typedef unsigned char __type; };
1705 struct __make_unsigned<short>
1706 { typedef unsigned short __type; };
1709 struct __make_unsigned<int>
1710 { typedef unsigned int __type; };
1713 struct __make_unsigned<long>
1714 { typedef unsigned long __type; };
1717 struct __make_unsigned<long long>
1718 { typedef unsigned long long __type; };
1720 #if defined(__GLIBCXX_TYPE_INT_N_0)
1722 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_0>
1723 { typedef unsigned __GLIBCXX_TYPE_INT_N_0 __type; };
1725 #if defined(__GLIBCXX_TYPE_INT_N_1)
1727 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_1>
1728 { typedef unsigned __GLIBCXX_TYPE_INT_N_1 __type; };
1730 #if defined(__GLIBCXX_TYPE_INT_N_2)
1732 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_2>
1733 { typedef unsigned __GLIBCXX_TYPE_INT_N_2 __type; };
1735 #if defined(__GLIBCXX_TYPE_INT_N_3)
1737 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_3>
1738 { typedef unsigned __GLIBCXX_TYPE_INT_N_3 __type; };
1741 // Select between integral and enum: not possible to be both.
1742 template<typename _Tp,
1743 bool _IsInt = is_integral<_Tp>::value,
1744 bool _IsEnum = is_enum<_Tp>::value>
1745 class __make_unsigned_selector;
1747 template<typename _Tp>
1748 class __make_unsigned_selector<_Tp, true, false>
1750 using __unsigned_type
1751 = typename __make_unsigned<__remove_cv_t<_Tp>>::__type;
1755 = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1758 class __make_unsigned_selector_base
1761 template<typename...> struct _List { };
1763 template<typename _Tp, typename... _Up>
1764 struct _List<_Tp, _Up...> : _List<_Up...>
1765 { static constexpr size_t __size = sizeof(_Tp); };
1767 template<size_t _Sz, typename _Tp, bool = (_Sz <= _Tp::__size)>
1770 template<size_t _Sz, typename _Uint, typename... _UInts>
1771 struct __select<_Sz, _List<_Uint, _UInts...>, true>
1772 { using __type = _Uint; };
1774 template<size_t _Sz, typename _Uint, typename... _UInts>
1775 struct __select<_Sz, _List<_Uint, _UInts...>, false>
1776 : __select<_Sz, _List<_UInts...>>
1780 // Choose unsigned integer type with the smallest rank and same size as _Tp
1781 template<typename _Tp>
1782 class __make_unsigned_selector<_Tp, false, true>
1783 : __make_unsigned_selector_base
1785 // With -fshort-enums, an enum may be as small as a char.
1786 using _UInts = _List<unsigned char, unsigned short, unsigned int,
1787 unsigned long, unsigned long long>;
1789 using __unsigned_type = typename __select<sizeof(_Tp), _UInts>::__type;
1793 = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1796 // wchar_t, char8_t, char16_t and char32_t are integral types but are
1797 // neither signed integer types nor unsigned integer types, so must be
1798 // transformed to the unsigned integer type with the smallest rank.
1799 // Use the partial specialization for enumeration types to do that.
1800 #ifdef __WCHAR_TYPE__
1802 struct __make_unsigned<wchar_t>
1805 = typename __make_unsigned_selector<wchar_t, false, true>::__type;
1809 #ifdef _GLIBCXX_USE_CHAR8_T
1811 struct __make_unsigned<char8_t>
1814 = typename __make_unsigned_selector<char8_t, false, true>::__type;
1819 struct __make_unsigned<char16_t>
1822 = typename __make_unsigned_selector<char16_t, false, true>::__type;
1826 struct __make_unsigned<char32_t>
1829 = typename __make_unsigned_selector<char32_t, false, true>::__type;
1833 // Given an integral/enum type, return the corresponding unsigned
1835 // Primary template.
1837 template<typename _Tp>
1838 struct make_unsigned
1839 { typedef typename __make_unsigned_selector<_Tp>::__type type; };
1841 // Integral, but don't define.
1843 struct make_unsigned<bool>;
1845 /// @cond undocumented
1847 // Utility for finding the signed versions of unsigned integral types.
1848 template<typename _Tp>
1849 struct __make_signed
1850 { typedef _Tp __type; };
1853 struct __make_signed<char>
1854 { typedef signed char __type; };
1857 struct __make_signed<unsigned char>
1858 { typedef signed char __type; };
1861 struct __make_signed<unsigned short>
1862 { typedef signed short __type; };
1865 struct __make_signed<unsigned int>
1866 { typedef signed int __type; };
1869 struct __make_signed<unsigned long>
1870 { typedef signed long __type; };
1873 struct __make_signed<unsigned long long>
1874 { typedef signed long long __type; };
1876 #if defined(__GLIBCXX_TYPE_INT_N_0)
1878 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_0>
1879 { typedef __GLIBCXX_TYPE_INT_N_0 __type; };
1881 #if defined(__GLIBCXX_TYPE_INT_N_1)
1883 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_1>
1884 { typedef __GLIBCXX_TYPE_INT_N_1 __type; };
1886 #if defined(__GLIBCXX_TYPE_INT_N_2)
1888 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_2>
1889 { typedef __GLIBCXX_TYPE_INT_N_2 __type; };
1891 #if defined(__GLIBCXX_TYPE_INT_N_3)
1893 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_3>
1894 { typedef __GLIBCXX_TYPE_INT_N_3 __type; };
1897 // Select between integral and enum: not possible to be both.
1898 template<typename _Tp,
1899 bool _IsInt = is_integral<_Tp>::value,
1900 bool _IsEnum = is_enum<_Tp>::value>
1901 class __make_signed_selector;
1903 template<typename _Tp>
1904 class __make_signed_selector<_Tp, true, false>
1907 = typename __make_signed<__remove_cv_t<_Tp>>::__type;
1911 = typename __match_cv_qualifiers<_Tp, __signed_type>::__type;
1914 // Choose signed integer type with the smallest rank and same size as _Tp
1915 template<typename _Tp>
1916 class __make_signed_selector<_Tp, false, true>
1918 typedef typename __make_unsigned_selector<_Tp>::__type __unsigned_type;
1921 typedef typename __make_signed_selector<__unsigned_type>::__type __type;
1924 // wchar_t, char16_t and char32_t are integral types but are neither
1925 // signed integer types nor unsigned integer types, so must be
1926 // transformed to the signed integer type with the smallest rank.
1927 // Use the partial specialization for enumeration types to do that.
1928 #if defined(__WCHAR_TYPE__)
1930 struct __make_signed<wchar_t>
1933 = typename __make_signed_selector<wchar_t, false, true>::__type;
1937 #if defined(_GLIBCXX_USE_CHAR8_T)
1939 struct __make_signed<char8_t>
1942 = typename __make_signed_selector<char8_t, false, true>::__type;
1947 struct __make_signed<char16_t>
1950 = typename __make_signed_selector<char16_t, false, true>::__type;
1954 struct __make_signed<char32_t>
1957 = typename __make_signed_selector<char32_t, false, true>::__type;
1961 // Given an integral/enum type, return the corresponding signed
1963 // Primary template.
1965 template<typename _Tp>
1967 { typedef typename __make_signed_selector<_Tp>::__type type; };
1969 // Integral, but don't define.
1971 struct make_signed<bool>;
1973 #if __cplusplus > 201103L
1974 /// Alias template for make_signed
1975 template<typename _Tp>
1976 using make_signed_t = typename make_signed<_Tp>::type;
1978 /// Alias template for make_unsigned
1979 template<typename _Tp>
1980 using make_unsigned_t = typename make_unsigned<_Tp>::type;
1983 // Array modifications.
1986 template<typename _Tp>
1987 struct remove_extent
1988 { typedef _Tp type; };
1990 template<typename _Tp, std::size_t _Size>
1991 struct remove_extent<_Tp[_Size]>
1992 { typedef _Tp type; };
1994 template<typename _Tp>
1995 struct remove_extent<_Tp[]>
1996 { typedef _Tp type; };
1998 /// remove_all_extents
1999 template<typename _Tp>
2000 struct remove_all_extents
2001 { typedef _Tp type; };
2003 template<typename _Tp, std::size_t _Size>
2004 struct remove_all_extents<_Tp[_Size]>
2005 { typedef typename remove_all_extents<_Tp>::type type; };
2007 template<typename _Tp>
2008 struct remove_all_extents<_Tp[]>
2009 { typedef typename remove_all_extents<_Tp>::type type; };
2011 #if __cplusplus > 201103L
2012 /// Alias template for remove_extent
2013 template<typename _Tp>
2014 using remove_extent_t = typename remove_extent<_Tp>::type;
2016 /// Alias template for remove_all_extents
2017 template<typename _Tp>
2018 using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
2021 // Pointer modifications.
2023 template<typename _Tp, typename>
2024 struct __remove_pointer_helper
2025 { typedef _Tp type; };
2027 template<typename _Tp, typename _Up>
2028 struct __remove_pointer_helper<_Tp, _Up*>
2029 { typedef _Up type; };
2032 template<typename _Tp>
2033 struct remove_pointer
2034 : public __remove_pointer_helper<_Tp, __remove_cv_t<_Tp>>
2037 template<typename _Tp, bool = __or_<__is_referenceable<_Tp>,
2038 is_void<_Tp>>::value>
2039 struct __add_pointer_helper
2040 { typedef _Tp type; };
2042 template<typename _Tp>
2043 struct __add_pointer_helper<_Tp, true>
2044 { typedef typename remove_reference<_Tp>::type* type; };
2047 template<typename _Tp>
2049 : public __add_pointer_helper<_Tp>
2052 #if __cplusplus > 201103L
2053 /// Alias template for remove_pointer
2054 template<typename _Tp>
2055 using remove_pointer_t = typename remove_pointer<_Tp>::type;
2057 /// Alias template for add_pointer
2058 template<typename _Tp>
2059 using add_pointer_t = typename add_pointer<_Tp>::type;
2062 template<std::size_t _Len>
2063 struct __aligned_storage_msa
2067 unsigned char __data[_Len];
2068 struct __attribute__((__aligned__)) { } __align;
2073 * @brief Alignment type.
2075 * The value of _Align is a default-alignment which shall be the
2076 * most stringent alignment requirement for any C++ object type
2077 * whose size is no greater than _Len (3.9). The member typedef
2078 * type shall be a POD type suitable for use as uninitialized
2079 * storage for any object whose size is at most _Len and whose
2080 * alignment is a divisor of _Align.
2082 template<std::size_t _Len, std::size_t _Align =
2083 __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2084 struct aligned_storage
2088 unsigned char __data[_Len];
2089 struct __attribute__((__aligned__((_Align)))) { } __align;
2093 template <typename... _Types>
2094 struct __strictest_alignment
2096 static const size_t _S_alignment = 0;
2097 static const size_t _S_size = 0;
2100 template <typename _Tp, typename... _Types>
2101 struct __strictest_alignment<_Tp, _Types...>
2103 static const size_t _S_alignment =
2104 alignof(_Tp) > __strictest_alignment<_Types...>::_S_alignment
2105 ? alignof(_Tp) : __strictest_alignment<_Types...>::_S_alignment;
2106 static const size_t _S_size =
2107 sizeof(_Tp) > __strictest_alignment<_Types...>::_S_size
2108 ? sizeof(_Tp) : __strictest_alignment<_Types...>::_S_size;
2112 * @brief Provide aligned storage for types.
2114 * [meta.trans.other]
2116 * Provides aligned storage for any of the provided types of at
2119 * @see aligned_storage
2121 template <size_t _Len, typename... _Types>
2122 struct aligned_union
2125 static_assert(sizeof...(_Types) != 0, "At least one type is required");
2127 using __strictest = __strictest_alignment<_Types...>;
2128 static const size_t _S_len = _Len > __strictest::_S_size
2129 ? _Len : __strictest::_S_size;
2131 /// The value of the strictest alignment of _Types.
2132 static const size_t alignment_value = __strictest::_S_alignment;
2134 typedef typename aligned_storage<_S_len, alignment_value>::type type;
2137 template <size_t _Len, typename... _Types>
2138 const size_t aligned_union<_Len, _Types...>::alignment_value;
2140 /// @cond undocumented
2142 // Decay trait for arrays and functions, used for perfect forwarding
2143 // in make_pair, make_tuple, etc.
2144 template<typename _Up,
2145 bool _IsArray = is_array<_Up>::value,
2146 bool _IsFunction = is_function<_Up>::value>
2147 struct __decay_selector;
2150 template<typename _Up>
2151 struct __decay_selector<_Up, false, false>
2152 { typedef __remove_cv_t<_Up> __type; };
2154 template<typename _Up>
2155 struct __decay_selector<_Up, true, false>
2156 { typedef typename remove_extent<_Up>::type* __type; };
2158 template<typename _Up>
2159 struct __decay_selector<_Up, false, true>
2160 { typedef typename add_pointer<_Up>::type __type; };
2164 template<typename _Tp>
2167 typedef typename remove_reference<_Tp>::type __remove_type;
2170 typedef typename __decay_selector<__remove_type>::__type type;
2173 /// @cond undocumented
2175 // Helper which adds a reference to a type when given a reference_wrapper
2176 template<typename _Tp>
2177 struct __strip_reference_wrapper
2182 template<typename _Tp>
2183 struct __strip_reference_wrapper<reference_wrapper<_Tp> >
2185 typedef _Tp& __type;
2188 // __decay_t (std::decay_t for C++11).
2189 template<typename _Tp>
2190 using __decay_t = typename decay<_Tp>::type;
2192 template<typename _Tp>
2193 using __decay_and_strip = __strip_reference_wrapper<__decay_t<_Tp>>;
2196 // Primary template.
2197 /// Define a member typedef `type` only if a boolean constant is true.
2198 template<bool, typename _Tp = void>
2202 // Partial specialization for true.
2203 template<typename _Tp>
2204 struct enable_if<true, _Tp>
2205 { typedef _Tp type; };
2207 /// @cond undocumented
2209 // __enable_if_t (std::enable_if_t for C++11)
2210 template<bool _Cond, typename _Tp = void>
2211 using __enable_if_t = typename enable_if<_Cond, _Tp>::type;
2213 // Helper for SFINAE constraints
2214 template<typename... _Cond>
2215 using _Require = __enable_if_t<__and_<_Cond...>::value>;
2217 // __remove_cvref_t (std::remove_cvref_t for C++11).
2218 template<typename _Tp>
2219 using __remove_cvref_t
2220 = typename remove_cv<typename remove_reference<_Tp>::type>::type;
2223 // Primary template.
2224 /// Define a member typedef @c type to one of two argument types.
2225 template<bool _Cond, typename _Iftrue, typename _Iffalse>
2227 { typedef _Iftrue type; };
2229 // Partial specialization for false.
2230 template<typename _Iftrue, typename _Iffalse>
2231 struct conditional<false, _Iftrue, _Iffalse>
2232 { typedef _Iffalse type; };
2235 template<typename... _Tp>
2238 // Sfinae-friendly common_type implementation:
2240 /// @cond undocumented
2241 struct __do_common_type_impl
2243 template<typename _Tp, typename _Up>
2245 = decltype(true ? std::declval<_Tp>() : std::declval<_Up>());
2247 // if decay_t<decltype(false ? declval<D1>() : declval<D2>())>
2248 // denotes a valid type, let C denote that type.
2249 template<typename _Tp, typename _Up>
2250 static __success_type<__decay_t<__cond_t<_Tp, _Up>>>
2253 #if __cplusplus > 201703L
2254 // Otherwise, if COND-RES(CREF(D1), CREF(D2)) denotes a type,
2255 // let C denote the type decay_t<COND-RES(CREF(D1), CREF(D2))>.
2256 template<typename _Tp, typename _Up>
2257 static __success_type<__remove_cvref_t<__cond_t<const _Tp&, const _Up&>>>
2261 template<typename, typename>
2262 static __failure_type
2265 template<typename _Tp, typename _Up>
2266 static decltype(_S_test_2<_Tp, _Up>(0))
2270 // If sizeof...(T) is zero, there shall be no member type.
2272 struct common_type<>
2275 // If sizeof...(T) is one, the same type, if any, as common_type_t<T0, T0>.
2276 template<typename _Tp0>
2277 struct common_type<_Tp0>
2278 : public common_type<_Tp0, _Tp0>
2281 // If sizeof...(T) is two, ...
2282 template<typename _Tp1, typename _Tp2,
2283 typename _Dp1 = __decay_t<_Tp1>, typename _Dp2 = __decay_t<_Tp2>>
2284 struct __common_type_impl
2286 // If is_same_v<T1, D1> is false or is_same_v<T2, D2> is false,
2287 // let C denote the same type, if any, as common_type_t<D1, D2>.
2288 using type = common_type<_Dp1, _Dp2>;
2291 template<typename _Tp1, typename _Tp2>
2292 struct __common_type_impl<_Tp1, _Tp2, _Tp1, _Tp2>
2293 : private __do_common_type_impl
2295 // Otherwise, if decay_t<decltype(false ? declval<D1>() : declval<D2>())>
2296 // denotes a valid type, let C denote that type.
2297 using type = decltype(_S_test<_Tp1, _Tp2>(0));
2300 // If sizeof...(T) is two, ...
2301 template<typename _Tp1, typename _Tp2>
2302 struct common_type<_Tp1, _Tp2>
2303 : public __common_type_impl<_Tp1, _Tp2>::type
2306 template<typename...>
2307 struct __common_type_pack
2310 template<typename, typename, typename = void>
2311 struct __common_type_fold;
2313 // If sizeof...(T) is greater than two, ...
2314 template<typename _Tp1, typename _Tp2, typename... _Rp>
2315 struct common_type<_Tp1, _Tp2, _Rp...>
2316 : public __common_type_fold<common_type<_Tp1, _Tp2>,
2317 __common_type_pack<_Rp...>>
2320 // Let C denote the same type, if any, as common_type_t<T1, T2>.
2321 // If there is such a type C, type shall denote the same type, if any,
2322 // as common_type_t<C, R...>.
2323 template<typename _CTp, typename... _Rp>
2324 struct __common_type_fold<_CTp, __common_type_pack<_Rp...>,
2325 __void_t<typename _CTp::type>>
2326 : public common_type<typename _CTp::type, _Rp...>
2329 // Otherwise, there shall be no member type.
2330 template<typename _CTp, typename _Rp>
2331 struct __common_type_fold<_CTp, _Rp, void>
2334 template<typename _Tp, bool = is_enum<_Tp>::value>
2335 struct __underlying_type_impl
2337 using type = __underlying_type(_Tp);
2340 template<typename _Tp>
2341 struct __underlying_type_impl<_Tp, false>
2345 /// The underlying type of an enum.
2346 template<typename _Tp>
2347 struct underlying_type
2348 : public __underlying_type_impl<_Tp>
2351 /// @cond undocumented
2352 template<typename _Tp>
2353 struct __declval_protector
2355 static const bool __stop = false;
2359 /** Utility to simplify expressions used in unevaluated operands
2361 * @ingroup utilities
2363 template<typename _Tp>
2364 auto declval() noexcept -> decltype(__declval<_Tp>(0))
2366 static_assert(__declval_protector<_Tp>::__stop,
2367 "declval() must not be used!");
2368 return __declval<_Tp>(0);
2372 template<typename _Signature>
2375 // Sfinae-friendly result_of implementation:
2377 #define __cpp_lib_result_of_sfinae 201210
2379 /// @cond undocumented
2380 struct __invoke_memfun_ref { };
2381 struct __invoke_memfun_deref { };
2382 struct __invoke_memobj_ref { };
2383 struct __invoke_memobj_deref { };
2384 struct __invoke_other { };
2386 // Associate a tag type with a specialization of __success_type.
2387 template<typename _Tp, typename _Tag>
2388 struct __result_of_success : __success_type<_Tp>
2389 { using __invoke_type = _Tag; };
2391 // [func.require] paragraph 1 bullet 1:
2392 struct __result_of_memfun_ref_impl
2394 template<typename _Fp, typename _Tp1, typename... _Args>
2395 static __result_of_success<decltype(
2396 (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
2397 ), __invoke_memfun_ref> _S_test(int);
2399 template<typename...>
2400 static __failure_type _S_test(...);
2403 template<typename _MemPtr, typename _Arg, typename... _Args>
2404 struct __result_of_memfun_ref
2405 : private __result_of_memfun_ref_impl
2407 typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2410 // [func.require] paragraph 1 bullet 2:
2411 struct __result_of_memfun_deref_impl
2413 template<typename _Fp, typename _Tp1, typename... _Args>
2414 static __result_of_success<decltype(
2415 ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
2416 ), __invoke_memfun_deref> _S_test(int);
2418 template<typename...>
2419 static __failure_type _S_test(...);
2422 template<typename _MemPtr, typename _Arg, typename... _Args>
2423 struct __result_of_memfun_deref
2424 : private __result_of_memfun_deref_impl
2426 typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2429 // [func.require] paragraph 1 bullet 3:
2430 struct __result_of_memobj_ref_impl
2432 template<typename _Fp, typename _Tp1>
2433 static __result_of_success<decltype(
2434 std::declval<_Tp1>().*std::declval<_Fp>()
2435 ), __invoke_memobj_ref> _S_test(int);
2437 template<typename, typename>
2438 static __failure_type _S_test(...);
2441 template<typename _MemPtr, typename _Arg>
2442 struct __result_of_memobj_ref
2443 : private __result_of_memobj_ref_impl
2445 typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2448 // [func.require] paragraph 1 bullet 4:
2449 struct __result_of_memobj_deref_impl
2451 template<typename _Fp, typename _Tp1>
2452 static __result_of_success<decltype(
2453 (*std::declval<_Tp1>()).*std::declval<_Fp>()
2454 ), __invoke_memobj_deref> _S_test(int);
2456 template<typename, typename>
2457 static __failure_type _S_test(...);
2460 template<typename _MemPtr, typename _Arg>
2461 struct __result_of_memobj_deref
2462 : private __result_of_memobj_deref_impl
2464 typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2467 template<typename _MemPtr, typename _Arg>
2468 struct __result_of_memobj;
2470 template<typename _Res, typename _Class, typename _Arg>
2471 struct __result_of_memobj<_Res _Class::*, _Arg>
2473 typedef __remove_cvref_t<_Arg> _Argval;
2474 typedef _Res _Class::* _MemPtr;
2475 typedef typename conditional<__or_<is_same<_Argval, _Class>,
2476 is_base_of<_Class, _Argval>>::value,
2477 __result_of_memobj_ref<_MemPtr, _Arg>,
2478 __result_of_memobj_deref<_MemPtr, _Arg>
2482 template<typename _MemPtr, typename _Arg, typename... _Args>
2483 struct __result_of_memfun;
2485 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2486 struct __result_of_memfun<_Res _Class::*, _Arg, _Args...>
2488 typedef typename remove_reference<_Arg>::type _Argval;
2489 typedef _Res _Class::* _MemPtr;
2490 typedef typename conditional<is_base_of<_Class, _Argval>::value,
2491 __result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
2492 __result_of_memfun_deref<_MemPtr, _Arg, _Args...>
2496 // _GLIBCXX_RESOLVE_LIB_DEFECTS
2497 // 2219. INVOKE-ing a pointer to member with a reference_wrapper
2498 // as the object expression
2500 // Used by result_of, invoke etc. to unwrap a reference_wrapper.
2501 template<typename _Tp, typename _Up = __remove_cvref_t<_Tp>>
2507 template<typename _Tp, typename _Up>
2508 struct __inv_unwrap<_Tp, reference_wrapper<_Up>>
2513 template<bool, bool, typename _Functor, typename... _ArgTypes>
2514 struct __result_of_impl
2516 typedef __failure_type type;
2519 template<typename _MemPtr, typename _Arg>
2520 struct __result_of_impl<true, false, _MemPtr, _Arg>
2521 : public __result_of_memobj<__decay_t<_MemPtr>,
2522 typename __inv_unwrap<_Arg>::type>
2525 template<typename _MemPtr, typename _Arg, typename... _Args>
2526 struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
2527 : public __result_of_memfun<__decay_t<_MemPtr>,
2528 typename __inv_unwrap<_Arg>::type, _Args...>
2531 // [func.require] paragraph 1 bullet 5:
2532 struct __result_of_other_impl
2534 template<typename _Fn, typename... _Args>
2535 static __result_of_success<decltype(
2536 std::declval<_Fn>()(std::declval<_Args>()...)
2537 ), __invoke_other> _S_test(int);
2539 template<typename...>
2540 static __failure_type _S_test(...);
2543 template<typename _Functor, typename... _ArgTypes>
2544 struct __result_of_impl<false, false, _Functor, _ArgTypes...>
2545 : private __result_of_other_impl
2547 typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type;
2550 // __invoke_result (std::invoke_result for C++11)
2551 template<typename _Functor, typename... _ArgTypes>
2552 struct __invoke_result
2553 : public __result_of_impl<
2554 is_member_object_pointer<
2555 typename remove_reference<_Functor>::type
2557 is_member_function_pointer<
2558 typename remove_reference<_Functor>::type
2560 _Functor, _ArgTypes...
2565 template<typename _Functor, typename... _ArgTypes>
2566 struct result_of<_Functor(_ArgTypes...)>
2567 : public __invoke_result<_Functor, _ArgTypes...>
2570 #if __cplusplus >= 201402L
2571 /// Alias template for aligned_storage
2572 template<size_t _Len, size_t _Align =
2573 __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2574 using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
2576 template <size_t _Len, typename... _Types>
2577 using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
2579 /// Alias template for decay
2580 template<typename _Tp>
2581 using decay_t = typename decay<_Tp>::type;
2583 /// Alias template for enable_if
2584 template<bool _Cond, typename _Tp = void>
2585 using enable_if_t = typename enable_if<_Cond, _Tp>::type;
2587 /// Alias template for conditional
2588 template<bool _Cond, typename _Iftrue, typename _Iffalse>
2589 using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
2591 /// Alias template for common_type
2592 template<typename... _Tp>
2593 using common_type_t = typename common_type<_Tp...>::type;
2595 /// Alias template for underlying_type
2596 template<typename _Tp>
2597 using underlying_type_t = typename underlying_type<_Tp>::type;
2599 /// Alias template for result_of
2600 template<typename _Tp>
2601 using result_of_t = typename result_of<_Tp>::type;
2604 #if __cplusplus >= 201703L || !defined(__STRICT_ANSI__) // c++17 or gnu++11
2605 #define __cpp_lib_void_t 201411
2606 /// A metafunction that always yields void, used for detecting valid types.
2607 template<typename...> using void_t = void;
2610 /// @cond undocumented
2612 /// Implementation of the detection idiom (negative case).
2613 template<typename _Default, typename _AlwaysVoid,
2614 template<typename...> class _Op, typename... _Args>
2617 using value_t = false_type;
2618 using type = _Default;
2621 /// Implementation of the detection idiom (positive case).
2622 template<typename _Default, template<typename...> class _Op,
2624 struct __detector<_Default, __void_t<_Op<_Args...>>, _Op, _Args...>
2626 using value_t = true_type;
2627 using type = _Op<_Args...>;
2630 // Detect whether _Op<_Args...> is a valid type, use _Default if not.
2631 template<typename _Default, template<typename...> class _Op,
2633 using __detected_or = __detector<_Default, void, _Op, _Args...>;
2635 // _Op<_Args...> if that is a valid type, otherwise _Default.
2636 template<typename _Default, template<typename...> class _Op,
2638 using __detected_or_t
2639 = typename __detected_or<_Default, _Op, _Args...>::type;
2642 * Use SFINAE to determine if the type _Tp has a publicly-accessible
2643 * member type _NTYPE.
2645 #define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
2646 template<typename _Tp, typename = __void_t<>> \
2647 struct __has_##_NTYPE \
2650 template<typename _Tp> \
2651 struct __has_##_NTYPE<_Tp, __void_t<typename _Tp::_NTYPE>> \
2655 template <typename _Tp>
2656 struct __is_swappable;
2658 template <typename _Tp>
2659 struct __is_nothrow_swappable;
2662 struct __is_tuple_like_impl : false_type
2665 template<typename... _Tps>
2666 struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
2669 // Internal type trait that allows us to sfinae-protect tuple_cat.
2670 template<typename _Tp>
2671 struct __is_tuple_like
2672 : public __is_tuple_like_impl<__remove_cvref_t<_Tp>>::type
2676 template<typename _Tp>
2677 _GLIBCXX20_CONSTEXPR
2679 _Require<__not_<__is_tuple_like<_Tp>>,
2680 is_move_constructible<_Tp>,
2681 is_move_assignable<_Tp>>
2683 noexcept(__and_<is_nothrow_move_constructible<_Tp>,
2684 is_nothrow_move_assignable<_Tp>>::value);
2686 template<typename _Tp, size_t _Nm>
2687 _GLIBCXX20_CONSTEXPR
2689 __enable_if_t<__is_swappable<_Tp>::value>
2690 swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
2691 noexcept(__is_nothrow_swappable<_Tp>::value);
2693 /// @cond undocumented
2694 namespace __swappable_details {
2697 struct __do_is_swappable_impl
2699 template<typename _Tp, typename
2700 = decltype(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))>
2701 static true_type __test(int);
2704 static false_type __test(...);
2707 struct __do_is_nothrow_swappable_impl
2709 template<typename _Tp>
2710 static __bool_constant<
2711 noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))
2715 static false_type __test(...);
2718 } // namespace __swappable_details
2720 template<typename _Tp>
2721 struct __is_swappable_impl
2722 : public __swappable_details::__do_is_swappable_impl
2724 typedef decltype(__test<_Tp>(0)) type;
2727 template<typename _Tp>
2728 struct __is_nothrow_swappable_impl
2729 : public __swappable_details::__do_is_nothrow_swappable_impl
2731 typedef decltype(__test<_Tp>(0)) type;
2734 template<typename _Tp>
2735 struct __is_swappable
2736 : public __is_swappable_impl<_Tp>::type
2739 template<typename _Tp>
2740 struct __is_nothrow_swappable
2741 : public __is_nothrow_swappable_impl<_Tp>::type
2745 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
2746 #define __cpp_lib_is_swappable 201603
2747 /// Metafunctions used for detecting swappable types: p0185r1
2750 template<typename _Tp>
2752 : public __is_swappable_impl<_Tp>::type
2754 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2755 "template argument must be a complete class or an unbounded array");
2758 /// is_nothrow_swappable
2759 template<typename _Tp>
2760 struct is_nothrow_swappable
2761 : public __is_nothrow_swappable_impl<_Tp>::type
2763 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2764 "template argument must be a complete class or an unbounded array");
2767 #if __cplusplus >= 201402L
2769 template<typename _Tp>
2770 _GLIBCXX17_INLINE constexpr bool is_swappable_v =
2771 is_swappable<_Tp>::value;
2773 /// is_nothrow_swappable_v
2774 template<typename _Tp>
2775 _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_v =
2776 is_nothrow_swappable<_Tp>::value;
2777 #endif // __cplusplus >= 201402L
2779 /// @cond undocumented
2780 namespace __swappable_with_details {
2783 struct __do_is_swappable_with_impl
2785 template<typename _Tp, typename _Up, typename
2786 = decltype(swap(std::declval<_Tp>(), std::declval<_Up>())),
2788 = decltype(swap(std::declval<_Up>(), std::declval<_Tp>()))>
2789 static true_type __test(int);
2791 template<typename, typename>
2792 static false_type __test(...);
2795 struct __do_is_nothrow_swappable_with_impl
2797 template<typename _Tp, typename _Up>
2798 static __bool_constant<
2799 noexcept(swap(std::declval<_Tp>(), std::declval<_Up>()))
2801 noexcept(swap(std::declval<_Up>(), std::declval<_Tp>()))
2804 template<typename, typename>
2805 static false_type __test(...);
2808 } // namespace __swappable_with_details
2810 template<typename _Tp, typename _Up>
2811 struct __is_swappable_with_impl
2812 : public __swappable_with_details::__do_is_swappable_with_impl
2814 typedef decltype(__test<_Tp, _Up>(0)) type;
2817 // Optimization for the homogenous lvalue case, not required:
2818 template<typename _Tp>
2819 struct __is_swappable_with_impl<_Tp&, _Tp&>
2820 : public __swappable_details::__do_is_swappable_impl
2822 typedef decltype(__test<_Tp&>(0)) type;
2825 template<typename _Tp, typename _Up>
2826 struct __is_nothrow_swappable_with_impl
2827 : public __swappable_with_details::__do_is_nothrow_swappable_with_impl
2829 typedef decltype(__test<_Tp, _Up>(0)) type;
2832 // Optimization for the homogenous lvalue case, not required:
2833 template<typename _Tp>
2834 struct __is_nothrow_swappable_with_impl<_Tp&, _Tp&>
2835 : public __swappable_details::__do_is_nothrow_swappable_impl
2837 typedef decltype(__test<_Tp&>(0)) type;
2841 /// is_swappable_with
2842 template<typename _Tp, typename _Up>
2843 struct is_swappable_with
2844 : public __is_swappable_with_impl<_Tp, _Up>::type
2846 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2847 "first template argument must be a complete class or an unbounded array");
2848 static_assert(std::__is_complete_or_unbounded(__type_identity<_Up>{}),
2849 "second template argument must be a complete class or an unbounded array");
2852 /// is_nothrow_swappable_with
2853 template<typename _Tp, typename _Up>
2854 struct is_nothrow_swappable_with
2855 : public __is_nothrow_swappable_with_impl<_Tp, _Up>::type
2857 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2858 "first template argument must be a complete class or an unbounded array");
2859 static_assert(std::__is_complete_or_unbounded(__type_identity<_Up>{}),
2860 "second template argument must be a complete class or an unbounded array");
2863 #if __cplusplus >= 201402L
2864 /// is_swappable_with_v
2865 template<typename _Tp, typename _Up>
2866 _GLIBCXX17_INLINE constexpr bool is_swappable_with_v =
2867 is_swappable_with<_Tp, _Up>::value;
2869 /// is_nothrow_swappable_with_v
2870 template<typename _Tp, typename _Up>
2871 _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_with_v =
2872 is_nothrow_swappable_with<_Tp, _Up>::value;
2873 #endif // __cplusplus >= 201402L
2875 #endif// c++1z or gnu++11
2877 /// @cond undocumented
2879 // __is_invocable (std::is_invocable for C++11)
2881 // The primary template is used for invalid INVOKE expressions.
2882 template<typename _Result, typename _Ret,
2883 bool = is_void<_Ret>::value, typename = void>
2884 struct __is_invocable_impl : false_type { };
2886 // Used for valid INVOKE and INVOKE<void> expressions.
2887 template<typename _Result, typename _Ret>
2888 struct __is_invocable_impl<_Result, _Ret,
2889 /* is_void<_Ret> = */ true,
2890 __void_t<typename _Result::type>>
2894 #pragma GCC diagnostic push
2895 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
2896 // Used for INVOKE<R> expressions to check the implicit conversion to R.
2897 template<typename _Result, typename _Ret>
2898 struct __is_invocable_impl<_Result, _Ret,
2899 /* is_void<_Ret> = */ false,
2900 __void_t<typename _Result::type>>
2903 // The type of the INVOKE expression.
2904 // Unlike declval, this doesn't add_rvalue_reference.
2905 static typename _Result::type _S_get();
2907 template<typename _Tp>
2908 static void _S_conv(_Tp);
2910 // This overload is viable if INVOKE(f, args...) can convert to _Tp.
2911 template<typename _Tp, typename = decltype(_S_conv<_Tp>(_S_get()))>
2915 template<typename _Tp>
2920 using type = decltype(_S_test<_Ret>(1));
2922 #pragma GCC diagnostic pop
2924 template<typename _Fn, typename... _ArgTypes>
2925 struct __is_invocable
2926 : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2929 template<typename _Fn, typename _Tp, typename... _Args>
2930 constexpr bool __call_is_nt(__invoke_memfun_ref)
2932 using _Up = typename __inv_unwrap<_Tp>::type;
2933 return noexcept((std::declval<_Up>().*std::declval<_Fn>())(
2934 std::declval<_Args>()...));
2937 template<typename _Fn, typename _Tp, typename... _Args>
2938 constexpr bool __call_is_nt(__invoke_memfun_deref)
2940 return noexcept(((*std::declval<_Tp>()).*std::declval<_Fn>())(
2941 std::declval<_Args>()...));
2944 template<typename _Fn, typename _Tp>
2945 constexpr bool __call_is_nt(__invoke_memobj_ref)
2947 using _Up = typename __inv_unwrap<_Tp>::type;
2948 return noexcept(std::declval<_Up>().*std::declval<_Fn>());
2951 template<typename _Fn, typename _Tp>
2952 constexpr bool __call_is_nt(__invoke_memobj_deref)
2954 return noexcept((*std::declval<_Tp>()).*std::declval<_Fn>());
2957 template<typename _Fn, typename... _Args>
2958 constexpr bool __call_is_nt(__invoke_other)
2960 return noexcept(std::declval<_Fn>()(std::declval<_Args>()...));
2963 template<typename _Result, typename _Fn, typename... _Args>
2964 struct __call_is_nothrow
2966 std::__call_is_nt<_Fn, _Args...>(typename _Result::__invoke_type{})
2970 template<typename _Fn, typename... _Args>
2971 using __call_is_nothrow_
2972 = __call_is_nothrow<__invoke_result<_Fn, _Args...>, _Fn, _Args...>;
2974 // __is_nothrow_invocable (std::is_nothrow_invocable for C++11)
2975 template<typename _Fn, typename... _Args>
2976 struct __is_nothrow_invocable
2977 : __and_<__is_invocable<_Fn, _Args...>,
2978 __call_is_nothrow_<_Fn, _Args...>>::type
2981 #pragma GCC diagnostic push
2982 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
2983 struct __nonesuchbase {};
2984 struct __nonesuch : private __nonesuchbase {
2985 ~__nonesuch() = delete;
2986 __nonesuch(__nonesuch const&) = delete;
2987 void operator=(__nonesuch const&) = delete;
2989 #pragma GCC diagnostic pop
2992 #if __cplusplus >= 201703L
2993 # define __cpp_lib_is_invocable 201703
2995 /// std::invoke_result
2996 template<typename _Functor, typename... _ArgTypes>
2997 struct invoke_result
2998 : public __invoke_result<_Functor, _ArgTypes...>
3000 static_assert(std::__is_complete_or_unbounded(__type_identity<_Functor>{}),
3001 "_Functor must be a complete class or an unbounded array");
3002 static_assert((std::__is_complete_or_unbounded(
3003 __type_identity<_ArgTypes>{}) && ...),
3004 "each argument type must be a complete class or an unbounded array");
3007 /// std::invoke_result_t
3008 template<typename _Fn, typename... _Args>
3009 using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
3011 /// std::is_invocable
3012 template<typename _Fn, typename... _ArgTypes>
3014 : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
3016 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
3017 "_Fn must be a complete class or an unbounded array");
3018 static_assert((std::__is_complete_or_unbounded(
3019 __type_identity<_ArgTypes>{}) && ...),
3020 "each argument type must be a complete class or an unbounded array");
3023 /// std::is_invocable_r
3024 template<typename _Ret, typename _Fn, typename... _ArgTypes>
3025 struct is_invocable_r
3026 : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>::type
3028 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
3029 "_Fn must be a complete class or an unbounded array");
3030 static_assert((std::__is_complete_or_unbounded(
3031 __type_identity<_ArgTypes>{}) && ...),
3032 "each argument type must be a complete class or an unbounded array");
3033 static_assert(std::__is_complete_or_unbounded(__type_identity<_Ret>{}),
3034 "_Ret must be a complete class or an unbounded array");
3037 /// std::is_nothrow_invocable
3038 template<typename _Fn, typename... _ArgTypes>
3039 struct is_nothrow_invocable
3040 : __and_<__is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>,
3041 __call_is_nothrow_<_Fn, _ArgTypes...>>::type
3043 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
3044 "_Fn must be a complete class or an unbounded array");
3045 static_assert((std::__is_complete_or_unbounded(
3046 __type_identity<_ArgTypes>{}) && ...),
3047 "each argument type must be a complete class or an unbounded array");
3050 /// @cond undocumented
3051 template<typename _Result, typename _Ret, typename = void>
3052 struct __is_nt_invocable_impl : false_type { };
3054 template<typename _Result, typename _Ret>
3055 struct __is_nt_invocable_impl<_Result, _Ret,
3056 __void_t<typename _Result::type>>
3057 : __or_<is_void<_Ret>,
3058 __is_nothrow_convertible<typename _Result::type, _Ret>>
3062 /// std::is_nothrow_invocable_r
3063 template<typename _Ret, typename _Fn, typename... _ArgTypes>
3064 struct is_nothrow_invocable_r
3065 : __and_<__is_nt_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>,
3066 __call_is_nothrow_<_Fn, _ArgTypes...>>::type
3068 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
3069 "_Fn must be a complete class or an unbounded array");
3070 static_assert((std::__is_complete_or_unbounded(
3071 __type_identity<_ArgTypes>{}) && ...),
3072 "each argument type must be a complete class or an unbounded array");
3073 static_assert(std::__is_complete_or_unbounded(__type_identity<_Ret>{}),
3074 "_Ret must be a complete class or an unbounded array");
3078 #if __cplusplus >= 201703L
3079 # define __cpp_lib_type_trait_variable_templates 201510L
3081 * @defgroup variable_templates Variable templates for type traits.
3082 * @ingroup metaprogramming
3084 * The variable `is_foo_v<T>` is a boolean constant with the same value
3085 * as the type trait `is_foo<T>::value`.
3090 /** @ingroup variable_templates
3093 template <typename _Tp>
3094 inline constexpr bool is_void_v = is_void<_Tp>::value;
3095 template <typename _Tp>
3096 inline constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
3097 template <typename _Tp>
3098 inline constexpr bool is_integral_v = is_integral<_Tp>::value;
3099 template <typename _Tp>
3100 inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
3101 template <typename _Tp>
3102 inline constexpr bool is_array_v = is_array<_Tp>::value;
3103 template <typename _Tp>
3104 inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;
3105 template <typename _Tp>
3106 inline constexpr bool is_lvalue_reference_v =
3107 is_lvalue_reference<_Tp>::value;
3108 template <typename _Tp>
3109 inline constexpr bool is_rvalue_reference_v =
3110 is_rvalue_reference<_Tp>::value;
3111 template <typename _Tp>
3112 inline constexpr bool is_member_object_pointer_v =
3113 is_member_object_pointer<_Tp>::value;
3114 template <typename _Tp>
3115 inline constexpr bool is_member_function_pointer_v =
3116 is_member_function_pointer<_Tp>::value;
3117 template <typename _Tp>
3118 inline constexpr bool is_enum_v = is_enum<_Tp>::value;
3119 template <typename _Tp>
3120 inline constexpr bool is_union_v = is_union<_Tp>::value;
3121 template <typename _Tp>
3122 inline constexpr bool is_class_v = is_class<_Tp>::value;
3123 template <typename _Tp>
3124 inline constexpr bool is_function_v = is_function<_Tp>::value;
3125 template <typename _Tp>
3126 inline constexpr bool is_reference_v = is_reference<_Tp>::value;
3127 template <typename _Tp>
3128 inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
3129 template <typename _Tp>
3130 inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
3131 template <typename _Tp>
3132 inline constexpr bool is_object_v = is_object<_Tp>::value;
3133 template <typename _Tp>
3134 inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
3135 template <typename _Tp>
3136 inline constexpr bool is_compound_v = is_compound<_Tp>::value;
3137 template <typename _Tp>
3138 inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value;
3139 template <typename _Tp>
3140 inline constexpr bool is_const_v = is_const<_Tp>::value;
3141 template <typename _Tp>
3142 inline constexpr bool is_volatile_v = is_volatile<_Tp>::value;
3143 template <typename _Tp>
3144 inline constexpr bool is_trivial_v = is_trivial<_Tp>::value;
3145 template <typename _Tp>
3146 inline constexpr bool is_trivially_copyable_v =
3147 is_trivially_copyable<_Tp>::value;
3148 template <typename _Tp>
3149 inline constexpr bool is_standard_layout_v = is_standard_layout<_Tp>::value;
3150 #pragma GCC diagnostic push
3151 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
3152 template <typename _Tp>
3153 _GLIBCXX20_DEPRECATED("use is_standard_layout_v && is_trivial_v instead")
3154 inline constexpr bool is_pod_v = is_pod<_Tp>::value;
3155 template <typename _Tp>
3156 _GLIBCXX17_DEPRECATED
3157 inline constexpr bool is_literal_type_v = is_literal_type<_Tp>::value;
3158 #pragma GCC diagnostic pop
3159 template <typename _Tp>
3160 inline constexpr bool is_empty_v = is_empty<_Tp>::value;
3161 template <typename _Tp>
3162 inline constexpr bool is_polymorphic_v = is_polymorphic<_Tp>::value;
3163 template <typename _Tp>
3164 inline constexpr bool is_abstract_v = is_abstract<_Tp>::value;
3165 template <typename _Tp>
3166 inline constexpr bool is_final_v = is_final<_Tp>::value;
3167 template <typename _Tp>
3168 inline constexpr bool is_signed_v = is_signed<_Tp>::value;
3169 template <typename _Tp>
3170 inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
3171 template <typename _Tp, typename... _Args>
3172 inline constexpr bool is_constructible_v =
3173 is_constructible<_Tp, _Args...>::value;
3174 template <typename _Tp>
3175 inline constexpr bool is_default_constructible_v =
3176 is_default_constructible<_Tp>::value;
3177 template <typename _Tp>
3178 inline constexpr bool is_copy_constructible_v =
3179 is_copy_constructible<_Tp>::value;
3180 template <typename _Tp>
3181 inline constexpr bool is_move_constructible_v =
3182 is_move_constructible<_Tp>::value;
3183 template <typename _Tp, typename _Up>
3184 inline constexpr bool is_assignable_v = is_assignable<_Tp, _Up>::value;
3185 template <typename _Tp>
3186 inline constexpr bool is_copy_assignable_v = is_copy_assignable<_Tp>::value;
3187 template <typename _Tp>
3188 inline constexpr bool is_move_assignable_v = is_move_assignable<_Tp>::value;
3189 template <typename _Tp>
3190 inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
3191 template <typename _Tp, typename... _Args>
3192 inline constexpr bool is_trivially_constructible_v =
3193 is_trivially_constructible<_Tp, _Args...>::value;
3194 template <typename _Tp>
3195 inline constexpr bool is_trivially_default_constructible_v =
3196 is_trivially_default_constructible<_Tp>::value;
3197 template <typename _Tp>
3198 inline constexpr bool is_trivially_copy_constructible_v =
3199 is_trivially_copy_constructible<_Tp>::value;
3200 template <typename _Tp>
3201 inline constexpr bool is_trivially_move_constructible_v =
3202 is_trivially_move_constructible<_Tp>::value;
3203 template <typename _Tp, typename _Up>
3204 inline constexpr bool is_trivially_assignable_v =
3205 is_trivially_assignable<_Tp, _Up>::value;
3206 template <typename _Tp>
3207 inline constexpr bool is_trivially_copy_assignable_v =
3208 is_trivially_copy_assignable<_Tp>::value;
3209 template <typename _Tp>
3210 inline constexpr bool is_trivially_move_assignable_v =
3211 is_trivially_move_assignable<_Tp>::value;
3212 template <typename _Tp>
3213 inline constexpr bool is_trivially_destructible_v =
3214 is_trivially_destructible<_Tp>::value;
3215 template <typename _Tp, typename... _Args>
3216 inline constexpr bool is_nothrow_constructible_v =
3217 is_nothrow_constructible<_Tp, _Args...>::value;
3218 template <typename _Tp>
3219 inline constexpr bool is_nothrow_default_constructible_v =
3220 is_nothrow_default_constructible<_Tp>::value;
3221 template <typename _Tp>
3222 inline constexpr bool is_nothrow_copy_constructible_v =
3223 is_nothrow_copy_constructible<_Tp>::value;
3224 template <typename _Tp>
3225 inline constexpr bool is_nothrow_move_constructible_v =
3226 is_nothrow_move_constructible<_Tp>::value;
3227 template <typename _Tp, typename _Up>
3228 inline constexpr bool is_nothrow_assignable_v =
3229 is_nothrow_assignable<_Tp, _Up>::value;
3230 template <typename _Tp>
3231 inline constexpr bool is_nothrow_copy_assignable_v =
3232 is_nothrow_copy_assignable<_Tp>::value;
3233 template <typename _Tp>
3234 inline constexpr bool is_nothrow_move_assignable_v =
3235 is_nothrow_move_assignable<_Tp>::value;
3236 template <typename _Tp>
3237 inline constexpr bool is_nothrow_destructible_v =
3238 is_nothrow_destructible<_Tp>::value;
3239 template <typename _Tp>
3240 inline constexpr bool has_virtual_destructor_v =
3241 has_virtual_destructor<_Tp>::value;
3242 template <typename _Tp>
3243 inline constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
3244 template <typename _Tp>
3245 inline constexpr size_t rank_v = rank<_Tp>::value;
3246 template <typename _Tp, unsigned _Idx = 0>
3247 inline constexpr size_t extent_v = extent<_Tp, _Idx>::value;
3248 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_SAME
3249 template <typename _Tp, typename _Up>
3250 inline constexpr bool is_same_v = __is_same(_Tp, _Up);
3252 template <typename _Tp, typename _Up>
3253 inline constexpr bool is_same_v = std::is_same<_Tp, _Up>::value;
3255 template <typename _Base, typename _Derived>
3256 inline constexpr bool is_base_of_v = is_base_of<_Base, _Derived>::value;
3257 template <typename _From, typename _To>
3258 inline constexpr bool is_convertible_v = is_convertible<_From, _To>::value;
3259 template<typename _Fn, typename... _Args>
3260 inline constexpr bool is_invocable_v = is_invocable<_Fn, _Args...>::value;
3261 template<typename _Fn, typename... _Args>
3262 inline constexpr bool is_nothrow_invocable_v
3263 = is_nothrow_invocable<_Fn, _Args...>::value;
3264 template<typename _Ret, typename _Fn, typename... _Args>
3265 inline constexpr bool is_invocable_r_v
3266 = is_invocable_r<_Ret, _Fn, _Args...>::value;
3267 template<typename _Ret, typename _Fn, typename... _Args>
3268 inline constexpr bool is_nothrow_invocable_r_v
3269 = is_nothrow_invocable_r<_Ret, _Fn, _Args...>::value;
3272 #ifdef _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP
3273 # define __cpp_lib_has_unique_object_representations 201606
3274 /// has_unique_object_representations
3275 template<typename _Tp>
3276 struct has_unique_object_representations
3277 : bool_constant<__has_unique_object_representations(
3278 remove_cv_t<remove_all_extents_t<_Tp>>
3281 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
3282 "template argument must be a complete class or an unbounded array");
3285 /// @ingroup variable_templates
3286 template<typename _Tp>
3287 inline constexpr bool has_unique_object_representations_v
3288 = has_unique_object_representations<_Tp>::value;
3291 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE
3292 # define __cpp_lib_is_aggregate 201703
3294 template<typename _Tp>
3296 : bool_constant<__is_aggregate(remove_cv_t<_Tp>)>
3299 /// @ingroup variable_templates
3300 template<typename _Tp>
3301 inline constexpr bool is_aggregate_v = is_aggregate<_Tp>::value;
3305 #if __cplusplus > 201703L
3306 #define __cpp_lib_remove_cvref 201711L
3308 /// Remove references and cv-qualifiers.
3309 template<typename _Tp>
3314 template<typename _Tp>
3315 struct remove_cvref<_Tp&>
3319 template<typename _Tp>
3320 struct remove_cvref<_Tp&&>
3324 template<typename _Tp>
3325 using remove_cvref_t = typename remove_cvref<_Tp>::type;
3327 #define __cpp_lib_type_identity 201806L
3328 /// Identity metafunction.
3329 template<typename _Tp>
3330 struct type_identity { using type = _Tp; };
3332 template<typename _Tp>
3333 using type_identity_t = typename type_identity<_Tp>::type;
3335 #define __cpp_lib_unwrap_ref 201811L
3337 /// Unwrap a reference_wrapper
3338 template<typename _Tp>
3339 struct unwrap_reference { using type = _Tp; };
3341 template<typename _Tp>
3342 struct unwrap_reference<reference_wrapper<_Tp>> { using type = _Tp&; };
3344 template<typename _Tp>
3345 using unwrap_reference_t = typename unwrap_reference<_Tp>::type;
3347 /// Decay type and if it's a reference_wrapper, unwrap it
3348 template<typename _Tp>
3349 struct unwrap_ref_decay { using type = unwrap_reference_t<decay_t<_Tp>>; };
3351 template<typename _Tp>
3352 using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
3354 #define __cpp_lib_bounded_array_traits 201902L
3356 /// True for a type that is an array of known bound.
3357 template<typename _Tp>
3358 struct is_bounded_array
3359 : public __is_array_known_bounds<_Tp>
3362 /// True for a type that is an array of unknown bound.
3363 template<typename _Tp>
3364 struct is_unbounded_array
3365 : public __is_array_unknown_bounds<_Tp>
3368 /// @ingroup variable_templates
3369 template<typename _Tp>
3370 inline constexpr bool is_bounded_array_v
3371 = is_bounded_array<_Tp>::value;
3373 /// @ingroup variable_templates
3374 template<typename _Tp>
3375 inline constexpr bool is_unbounded_array_v
3376 = is_unbounded_array<_Tp>::value;
3378 #if __cplusplus > 202002L
3379 #define __cpp_lib_is_scoped_enum 202011L
3384 template<typename _Tp>
3385 struct is_scoped_enum
3389 template<typename _Tp>
3390 requires __is_enum(_Tp)
3391 && requires(_Tp __t) { __t = __t; } // fails if incomplete
3392 struct is_scoped_enum<_Tp>
3393 : bool_constant<!requires(_Tp __t, void(*__f)(int)) { __f(__t); }>
3396 // FIXME remove this partial specialization and use remove_cv_t<_Tp> above
3397 // when PR c++/99968 is fixed.
3398 template<typename _Tp>
3399 requires __is_enum(_Tp)
3400 && requires(_Tp __t) { __t = __t; } // fails if incomplete
3401 struct is_scoped_enum<const _Tp>
3402 : bool_constant<!requires(_Tp __t, void(*__f)(int)) { __f(__t); }>
3406 * @ingroup variable_templates
3408 template<typename _Tp>
3409 inline constexpr bool is_scoped_enum_v = is_scoped_enum<_Tp>::value;
3412 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
3414 #define __cpp_lib_is_constant_evaluated 201811L
3416 /// Returns true only when called during constant evaluation.
3417 constexpr inline bool
3418 is_constant_evaluated() noexcept
3419 { return __builtin_is_constant_evaluated(); }
3423 /// @cond undocumented
3424 template<typename _From, typename _To>
3425 using __copy_cv = typename __match_cv_qualifiers<_From, _To>::__type;
3427 template<typename _Xp, typename _Yp>
3429 = decltype(false ? declval<_Xp(&)()>()() : declval<_Yp(&)()>()());
3431 template<typename _Ap, typename _Bp, typename = void>
3432 struct __common_ref_impl
3435 // [meta.trans.other], COMMON-REF(A, B)
3436 template<typename _Ap, typename _Bp>
3437 using __common_ref = typename __common_ref_impl<_Ap, _Bp>::type;
3439 // COND-RES(COPYCV(X, Y) &, COPYCV(Y, X) &)
3440 template<typename _Xp, typename _Yp>
3441 using __condres_cvref
3442 = __cond_res<__copy_cv<_Xp, _Yp>&, __copy_cv<_Yp, _Xp>&>;
3444 // If A and B are both lvalue reference types, ...
3445 template<typename _Xp, typename _Yp>
3446 struct __common_ref_impl<_Xp&, _Yp&, __void_t<__condres_cvref<_Xp, _Yp>>>
3447 : enable_if<is_reference_v<__condres_cvref<_Xp, _Yp>>,
3448 __condres_cvref<_Xp, _Yp>>
3451 // let C be remove_reference_t<COMMON-REF(X&, Y&)>&&
3452 template<typename _Xp, typename _Yp>
3453 using __common_ref_C = remove_reference_t<__common_ref<_Xp&, _Yp&>>&&;
3455 // If A and B are both rvalue reference types, ...
3456 template<typename _Xp, typename _Yp>
3457 struct __common_ref_impl<_Xp&&, _Yp&&,
3458 _Require<is_convertible<_Xp&&, __common_ref_C<_Xp, _Yp>>,
3459 is_convertible<_Yp&&, __common_ref_C<_Xp, _Yp>>>>
3460 { using type = __common_ref_C<_Xp, _Yp>; };
3462 // let D be COMMON-REF(const X&, Y&)
3463 template<typename _Xp, typename _Yp>
3464 using __common_ref_D = __common_ref<const _Xp&, _Yp&>;
3466 // If A is an rvalue reference and B is an lvalue reference, ...
3467 template<typename _Xp, typename _Yp>
3468 struct __common_ref_impl<_Xp&&, _Yp&,
3469 _Require<is_convertible<_Xp&&, __common_ref_D<_Xp, _Yp>>>>
3470 { using type = __common_ref_D<_Xp, _Yp>; };
3472 // If A is an lvalue reference and B is an rvalue reference, ...
3473 template<typename _Xp, typename _Yp>
3474 struct __common_ref_impl<_Xp&, _Yp&&>
3475 : __common_ref_impl<_Yp&&, _Xp&>
3479 template<typename _Tp, typename _Up,
3480 template<typename> class _TQual, template<typename> class _UQual>
3481 struct basic_common_reference
3484 /// @cond undocumented
3485 template<typename _Tp>
3487 { template<typename _Up> using __type = __copy_cv<_Tp, _Up>; };
3489 template<typename _Tp>
3491 { template<typename _Up> using __type = __copy_cv<_Tp, _Up>&; };
3493 template<typename _Tp>
3494 struct __xref<_Tp&&>
3495 { template<typename _Up> using __type = __copy_cv<_Tp, _Up>&&; };
3497 template<typename _Tp1, typename _Tp2>
3498 using __basic_common_ref
3499 = typename basic_common_reference<remove_cvref_t<_Tp1>,
3500 remove_cvref_t<_Tp2>,
3501 __xref<_Tp1>::template __type,
3502 __xref<_Tp2>::template __type>::type;
3505 template<typename... _Tp>
3506 struct common_reference;
3508 template<typename... _Tp>
3509 using common_reference_t = typename common_reference<_Tp...>::type;
3511 // If sizeof...(T) is zero, there shall be no member type.
3513 struct common_reference<>
3516 // If sizeof...(T) is one ...
3517 template<typename _Tp0>
3518 struct common_reference<_Tp0>
3519 { using type = _Tp0; };
3521 /// @cond undocumented
3522 template<typename _Tp1, typename _Tp2, int _Bullet = 1, typename = void>
3523 struct __common_reference_impl
3524 : __common_reference_impl<_Tp1, _Tp2, _Bullet + 1>
3527 // If sizeof...(T) is two ...
3528 template<typename _Tp1, typename _Tp2>
3529 struct common_reference<_Tp1, _Tp2>
3530 : __common_reference_impl<_Tp1, _Tp2>
3533 // If T1 and T2 are reference types and COMMON-REF(T1, T2) is well-formed, ...
3534 template<typename _Tp1, typename _Tp2>
3535 struct __common_reference_impl<_Tp1&, _Tp2&, 1,
3536 void_t<__common_ref<_Tp1&, _Tp2&>>>
3537 { using type = __common_ref<_Tp1&, _Tp2&>; };
3539 template<typename _Tp1, typename _Tp2>
3540 struct __common_reference_impl<_Tp1&&, _Tp2&&, 1,
3541 void_t<__common_ref<_Tp1&&, _Tp2&&>>>
3542 { using type = __common_ref<_Tp1&&, _Tp2&&>; };
3544 template<typename _Tp1, typename _Tp2>
3545 struct __common_reference_impl<_Tp1&, _Tp2&&, 1,
3546 void_t<__common_ref<_Tp1&, _Tp2&&>>>
3547 { using type = __common_ref<_Tp1&, _Tp2&&>; };
3549 template<typename _Tp1, typename _Tp2>
3550 struct __common_reference_impl<_Tp1&&, _Tp2&, 1,
3551 void_t<__common_ref<_Tp1&&, _Tp2&>>>
3552 { using type = __common_ref<_Tp1&&, _Tp2&>; };
3554 // Otherwise, if basic_common_reference<...>::type is well-formed, ...
3555 template<typename _Tp1, typename _Tp2>
3556 struct __common_reference_impl<_Tp1, _Tp2, 2,
3557 void_t<__basic_common_ref<_Tp1, _Tp2>>>
3558 { using type = __basic_common_ref<_Tp1, _Tp2>; };
3560 // Otherwise, if COND-RES(T1, T2) is well-formed, ...
3561 template<typename _Tp1, typename _Tp2>
3562 struct __common_reference_impl<_Tp1, _Tp2, 3,
3563 void_t<__cond_res<_Tp1, _Tp2>>>
3564 { using type = __cond_res<_Tp1, _Tp2>; };
3566 // Otherwise, if common_type_t<T1, T2> is well-formed, ...
3567 template<typename _Tp1, typename _Tp2>
3568 struct __common_reference_impl<_Tp1, _Tp2, 4,
3569 void_t<common_type_t<_Tp1, _Tp2>>>
3570 { using type = common_type_t<_Tp1, _Tp2>; };
3572 // Otherwise, there shall be no member type.
3573 template<typename _Tp1, typename _Tp2>
3574 struct __common_reference_impl<_Tp1, _Tp2, 5, void>
3577 // Otherwise, if sizeof...(T) is greater than two, ...
3578 template<typename _Tp1, typename _Tp2, typename... _Rest>
3579 struct common_reference<_Tp1, _Tp2, _Rest...>
3580 : __common_type_fold<common_reference<_Tp1, _Tp2>,
3581 __common_type_pack<_Rest...>>
3584 // Reuse __common_type_fold for common_reference<T1, T2, Rest...>
3585 template<typename _Tp1, typename _Tp2, typename... _Rest>
3586 struct __common_type_fold<common_reference<_Tp1, _Tp2>,
3587 __common_type_pack<_Rest...>,
3588 void_t<common_reference_t<_Tp1, _Tp2>>>
3589 : public common_reference<common_reference_t<_Tp1, _Tp2>, _Rest...>
3595 /// @} group metaprogramming
3597 _GLIBCXX_END_NAMESPACE_VERSION
3602 #endif // _GLIBCXX_TYPE_TRAITS