1// C++11 <type_traits> -*- C++ -*-
3// Copyright (C) 2007-2023 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>
40namespace std _GLIBCXX_VISIBILITY(default)
42_GLIBCXX_BEGIN_NAMESPACE_VERSION
44 template<typename _Tp>
45 class reference_wrapper;
48 * @defgroup metaprogramming Metaprogramming
51 * Template utilities for compile-time introspection and modification,
52 * including type classification traits, type property inspection traits
53 * and type transformation traits.
61 template<typename _Tp, _Tp __v>
62 struct integral_constant
64 static constexpr _Tp value = __v;
65 typedef _Tp value_type;
66 typedef integral_constant<_Tp, __v> type;
67 constexpr operator value_type() const noexcept { return value; }
68#if __cplusplus > 201103L
70#define __cpp_lib_integral_constant_callable 201304L
72 constexpr value_type operator()() const noexcept { return value; }
76#if ! __cpp_inline_variables
77 template<typename _Tp, _Tp __v>
78 constexpr _Tp integral_constant<_Tp, __v>::value;
81 /// The type used as a compile-time boolean with true value.
82 using true_type = integral_constant<bool, true>;
84 /// The type used as a compile-time boolean with false value.
85 using false_type = integral_constant<bool, false>;
87 /// @cond undocumented
88 /// bool_constant for C++11
90 using __bool_constant = integral_constant<bool, __v>;
93#if __cplusplus >= 201703L
94# define __cpp_lib_bool_constant 201505L
95 /// Alias template for compile-time boolean constant types.
98 using bool_constant = integral_constant<bool, __v>;
101 // Metaprogramming helper types.
104 /// Define a member typedef `type` only if a boolean constant is true.
105 template<bool, typename _Tp = void>
109 // Partial specialization for true.
110 template<typename _Tp>
111 struct enable_if<true, _Tp>
112 { typedef _Tp type; };
114 // __enable_if_t (std::enable_if_t for C++11)
115 template<bool _Cond, typename _Tp = void>
116 using __enable_if_t = typename enable_if<_Cond, _Tp>::type;
121 template<typename _Tp, typename>
126 struct __conditional<false>
128 template<typename, typename _Up>
132 // More efficient version of std::conditional_t for internal use (and C++11)
133 template<bool _Cond, typename _If, typename _Else>
134 using __conditional_t
135 = typename __conditional<_Cond>::template type<_If, _Else>;
137 /// @cond undocumented
138 template <typename _Type>
139 struct __type_identity
140 { using type = _Type; };
142 template<typename _Tp>
143 using __type_identity_t = typename __type_identity<_Tp>::type;
147 // A variadic alias template that resolves to its first argument.
148 template<typename _Tp, typename...>
149 using __first_t = _Tp;
151 // These are deliberately not defined.
152 template<typename... _Bn>
153 auto __or_fn(int) -> __first_t<false_type,
154 __enable_if_t<!bool(_Bn::value)>...>;
156 template<typename... _Bn>
157 auto __or_fn(...) -> true_type;
159 template<typename... _Bn>
160 auto __and_fn(int) -> __first_t<true_type,
161 __enable_if_t<bool(_Bn::value)>...>;
163 template<typename... _Bn>
164 auto __and_fn(...) -> false_type;
165 } // namespace detail
167 // Like C++17 std::dis/conjunction, but usable in C++11 and resolves
168 // to either true_type or false_type which allows for a more efficient
169 // implementation that avoids recursive class template instantiation.
170 template<typename... _Bn>
172 : decltype(__detail::__or_fn<_Bn...>(0))
175 template<typename... _Bn>
177 : decltype(__detail::__and_fn<_Bn...>(0))
180 template<typename _Pp>
182 : __bool_constant<!bool(_Pp::value)>
186#if __cplusplus >= 201703L
188 /// @cond undocumented
189 template<typename... _Bn>
190 inline constexpr bool __or_v = __or_<_Bn...>::value;
191 template<typename... _Bn>
192 inline constexpr bool __and_v = __and_<_Bn...>::value;
196 template<typename /* = void */, typename _B1, typename... _Bn>
197 struct __disjunction_impl
198 { using type = _B1; };
200 template<typename _B1, typename _B2, typename... _Bn>
201 struct __disjunction_impl<__enable_if_t<!bool(_B1::value)>, _B1, _B2, _Bn...>
202 { using type = typename __disjunction_impl<void, _B2, _Bn...>::type; };
204 template<typename /* = void */, typename _B1, typename... _Bn>
205 struct __conjunction_impl
206 { using type = _B1; };
208 template<typename _B1, typename _B2, typename... _Bn>
209 struct __conjunction_impl<__enable_if_t<bool(_B1::value)>, _B1, _B2, _Bn...>
210 { using type = typename __conjunction_impl<void, _B2, _Bn...>::type; };
211 } // namespace __detail
214#define __cpp_lib_logical_traits 201510L
216 template<typename... _Bn>
218 : __detail::__conjunction_impl<void, _Bn...>::type
226 template<typename... _Bn>
228 : __detail::__disjunction_impl<void, _Bn...>::type
236 template<typename _Pp>
241 /** @ingroup variable_templates
244 template<typename... _Bn>
245 inline constexpr bool conjunction_v = conjunction<_Bn...>::value;
247 template<typename... _Bn>
248 inline constexpr bool disjunction_v = disjunction<_Bn...>::value;
250 template<typename _Pp>
251 inline constexpr bool negation_v = negation<_Pp>::value;
256 // Forward declarations
268 /// @cond undocumented
270 struct __is_array_unknown_bounds;
272 // Helper functions that return false_type for incomplete classes,
273 // incomplete unions and arrays of known bound from those.
275 template <typename _Tp, size_t = sizeof(_Tp)>
276 constexpr true_type __is_complete_or_unbounded(__type_identity<_Tp>)
279 template <typename _TypeIdentity,
280 typename _NestedType = typename _TypeIdentity::type>
281 constexpr typename __or_<
282 is_reference<_NestedType>,
283 is_function<_NestedType>,
284 is_void<_NestedType>,
285 __is_array_unknown_bounds<_NestedType>
286 >::type __is_complete_or_unbounded(_TypeIdentity)
289 // __remove_cv_t (std::remove_cv_t for C++11).
290 template<typename _Tp>
291 using __remove_cv_t = typename remove_cv<_Tp>::type;
294 // Primary type categories.
297 template<typename _Tp>
299 : public false_type { };
303 : public true_type { };
306 struct is_void<const void>
307 : public true_type { };
310 struct is_void<volatile void>
311 : public true_type { };
314 struct is_void<const volatile void>
315 : public true_type { };
317 /// @cond undocumented
319 struct __is_integral_helper
320 : public false_type { };
323 struct __is_integral_helper<bool>
324 : public true_type { };
327 struct __is_integral_helper<char>
328 : public true_type { };
331 struct __is_integral_helper<signed char>
332 : public true_type { };
335 struct __is_integral_helper<unsigned char>
336 : public true_type { };
338 // We want is_integral<wchar_t> to be true (and make_signed/unsigned to work)
339 // even when libc doesn't provide working <wchar.h> and related functions,
340 // so don't check _GLIBCXX_USE_WCHAR_T here.
342 struct __is_integral_helper<wchar_t>
343 : public true_type { };
345#ifdef _GLIBCXX_USE_CHAR8_T
347 struct __is_integral_helper<char8_t>
348 : public true_type { };
352 struct __is_integral_helper<char16_t>
353 : public true_type { };
356 struct __is_integral_helper<char32_t>
357 : public true_type { };
360 struct __is_integral_helper<short>
361 : public true_type { };
364 struct __is_integral_helper<unsigned short>
365 : public true_type { };
368 struct __is_integral_helper<int>
369 : public true_type { };
372 struct __is_integral_helper<unsigned int>
373 : public true_type { };
376 struct __is_integral_helper<long>
377 : public true_type { };
380 struct __is_integral_helper<unsigned long>
381 : public true_type { };
384 struct __is_integral_helper<long long>
385 : public true_type { };
388 struct __is_integral_helper<unsigned long long>
389 : public true_type { };
391 // Conditionalizing on __STRICT_ANSI__ here will break any port that
392 // uses one of these types for size_t.
393#if defined(__GLIBCXX_TYPE_INT_N_0)
396 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_0>
397 : public true_type { };
401 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_0>
402 : public true_type { };
404#if defined(__GLIBCXX_TYPE_INT_N_1)
407 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_1>
408 : public true_type { };
412 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_1>
413 : public true_type { };
415#if defined(__GLIBCXX_TYPE_INT_N_2)
418 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_2>
419 : public true_type { };
423 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_2>
424 : public true_type { };
426#if defined(__GLIBCXX_TYPE_INT_N_3)
429 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_3>
430 : public true_type { };
434 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_3>
435 : public true_type { };
440 template<typename _Tp>
442 : public __is_integral_helper<__remove_cv_t<_Tp>>::type
445 /// @cond undocumented
447 struct __is_floating_point_helper
448 : public false_type { };
451 struct __is_floating_point_helper<float>
452 : public true_type { };
455 struct __is_floating_point_helper<double>
456 : public true_type { };
459 struct __is_floating_point_helper<long double>
460 : public true_type { };
462#ifdef __STDCPP_FLOAT16_T__
464 struct __is_floating_point_helper<_Float16>
465 : public true_type { };
468#ifdef __STDCPP_FLOAT32_T__
470 struct __is_floating_point_helper<_Float32>
471 : public true_type { };
474#ifdef __STDCPP_FLOAT64_T__
476 struct __is_floating_point_helper<_Float64>
477 : public true_type { };
480#ifdef __STDCPP_FLOAT128_T__
482 struct __is_floating_point_helper<_Float128>
483 : public true_type { };
486#ifdef __STDCPP_BFLOAT16_T__
488 struct __is_floating_point_helper<__gnu_cxx::__bfloat16_t>
489 : public true_type { };
492#if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
494 struct __is_floating_point_helper<__float128>
495 : public true_type { };
499 /// is_floating_point
500 template<typename _Tp>
501 struct is_floating_point
502 : public __is_floating_point_helper<__remove_cv_t<_Tp>>::type
508 : public false_type { };
510 template<typename _Tp, std::size_t _Size>
511 struct is_array<_Tp[_Size]>
512 : public true_type { };
514 template<typename _Tp>
515 struct is_array<_Tp[]>
516 : public true_type { };
519 struct __is_pointer_helper
520 : public false_type { };
522 template<typename _Tp>
523 struct __is_pointer_helper<_Tp*>
524 : public true_type { };
527 template<typename _Tp>
529 : public __is_pointer_helper<__remove_cv_t<_Tp>>::type
532 /// is_lvalue_reference
534 struct is_lvalue_reference
535 : public false_type { };
537 template<typename _Tp>
538 struct is_lvalue_reference<_Tp&>
539 : public true_type { };
541 /// is_rvalue_reference
543 struct is_rvalue_reference
544 : public false_type { };
546 template<typename _Tp>
547 struct is_rvalue_reference<_Tp&&>
548 : public true_type { };
551 struct __is_member_object_pointer_helper
552 : public false_type { };
554 template<typename _Tp, typename _Cp>
555 struct __is_member_object_pointer_helper<_Tp _Cp::*>
556 : public __not_<is_function<_Tp>>::type { };
558 /// is_member_object_pointer
559 template<typename _Tp>
560 struct is_member_object_pointer
561 : public __is_member_object_pointer_helper<__remove_cv_t<_Tp>>::type
565 struct __is_member_function_pointer_helper
566 : public false_type { };
568 template<typename _Tp, typename _Cp>
569 struct __is_member_function_pointer_helper<_Tp _Cp::*>
570 : public is_function<_Tp>::type { };
572 /// is_member_function_pointer
573 template<typename _Tp>
574 struct is_member_function_pointer
575 : public __is_member_function_pointer_helper<__remove_cv_t<_Tp>>::type
579 template<typename _Tp>
581 : public integral_constant<bool, __is_enum(_Tp)>
585 template<typename _Tp>
587 : public integral_constant<bool, __is_union(_Tp)>
591 template<typename _Tp>
593 : public integral_constant<bool, __is_class(_Tp)>
597 template<typename _Tp>
599 : public __bool_constant<!is_const<const _Tp>::value> { };
601 template<typename _Tp>
602 struct is_function<_Tp&>
603 : public false_type { };
605 template<typename _Tp>
606 struct is_function<_Tp&&>
607 : public false_type { };
609#define __cpp_lib_is_null_pointer 201309L
611 /// is_null_pointer (LWG 2247).
612 template<typename _Tp>
613 struct is_null_pointer
614 : public false_type { };
617 struct is_null_pointer<std::nullptr_t>
618 : public true_type { };
621 struct is_null_pointer<const std::nullptr_t>
622 : public true_type { };
625 struct is_null_pointer<volatile std::nullptr_t>
626 : public true_type { };
629 struct is_null_pointer<const volatile std::nullptr_t>
630 : public true_type { };
632 /// __is_nullptr_t (deprecated extension).
633 /// @deprecated Non-standard. Use `is_null_pointer` instead.
634 template<typename _Tp>
635 struct __is_nullptr_t
636 : public is_null_pointer<_Tp>
637 { } _GLIBCXX_DEPRECATED_SUGGEST("std::is_null_pointer");
639 // Composite type categories.
642 template<typename _Tp>
647 template<typename _Tp>
648 struct is_reference<_Tp&>
652 template<typename _Tp>
653 struct is_reference<_Tp&&>
658 template<typename _Tp>
660 : public __or_<is_integral<_Tp>, is_floating_point<_Tp>>::type
664 template<typename _Tp>
665 struct is_fundamental
666 : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
667 is_null_pointer<_Tp>>::type
671 template<typename _Tp>
673 : public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
678 struct is_member_pointer;
681 template<typename _Tp>
683 : public __or_<is_arithmetic<_Tp>, is_enum<_Tp>, is_pointer<_Tp>,
684 is_member_pointer<_Tp>, is_null_pointer<_Tp>>::type
688 template<typename _Tp>
690 : public __not_<is_fundamental<_Tp>>::type { };
692 /// @cond undocumented
693 template<typename _Tp>
694 struct __is_member_pointer_helper
695 : public false_type { };
697 template<typename _Tp, typename _Cp>
698 struct __is_member_pointer_helper<_Tp _Cp::*>
699 : public true_type { };
702 /// is_member_pointer
703 template<typename _Tp>
704 struct is_member_pointer
705 : public __is_member_pointer_helper<__remove_cv_t<_Tp>>::type
708 template<typename, typename>
711 /// @cond undocumented
712 template<typename _Tp, typename... _Types>
713 using __is_one_of = __or_<is_same<_Tp, _Types>...>;
715 // Check if a type is one of the signed integer types.
717 template<typename _Tp>
718 using __is_signed_integer = __is_one_of<__remove_cv_t<_Tp>,
719 signed char, signed short, signed int, signed long,
721#if defined(__GLIBCXX_TYPE_INT_N_0)
722 , signed __GLIBCXX_TYPE_INT_N_0
724#if defined(__GLIBCXX_TYPE_INT_N_1)
725 , signed __GLIBCXX_TYPE_INT_N_1
727#if defined(__GLIBCXX_TYPE_INT_N_2)
728 , signed __GLIBCXX_TYPE_INT_N_2
730#if defined(__GLIBCXX_TYPE_INT_N_3)
731 , signed __GLIBCXX_TYPE_INT_N_3
735 // Check if a type is one of the unsigned integer types.
737 template<typename _Tp>
738 using __is_unsigned_integer = __is_one_of<__remove_cv_t<_Tp>,
739 unsigned char, unsigned short, unsigned int, unsigned long,
741#if defined(__GLIBCXX_TYPE_INT_N_0)
742 , unsigned __GLIBCXX_TYPE_INT_N_0
744#if defined(__GLIBCXX_TYPE_INT_N_1)
745 , unsigned __GLIBCXX_TYPE_INT_N_1
747#if defined(__GLIBCXX_TYPE_INT_N_2)
748 , unsigned __GLIBCXX_TYPE_INT_N_2
750#if defined(__GLIBCXX_TYPE_INT_N_3)
751 , unsigned __GLIBCXX_TYPE_INT_N_3
755 // Check if a type is one of the signed or unsigned integer types.
756 template<typename _Tp>
757 using __is_standard_integer
758 = __or_<__is_signed_integer<_Tp>, __is_unsigned_integer<_Tp>>;
760 // __void_t (std::void_t for C++11)
761 template<typename...> using __void_t = void;
769 : public false_type { };
771 template<typename _Tp>
772 struct is_const<_Tp const>
773 : public true_type { };
778 : public false_type { };
780 template<typename _Tp>
781 struct is_volatile<_Tp volatile>
782 : public true_type { };
785 template<typename _Tp>
787 : public integral_constant<bool, __is_trivial(_Tp)>
789 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
790 "template argument must be a complete class or an unbounded array");
793 /// is_trivially_copyable
794 template<typename _Tp>
795 struct is_trivially_copyable
796 : public integral_constant<bool, __is_trivially_copyable(_Tp)>
798 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
799 "template argument must be a complete class or an unbounded array");
802 /// is_standard_layout
803 template<typename _Tp>
804 struct is_standard_layout
805 : public integral_constant<bool, __is_standard_layout(_Tp)>
807 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
808 "template argument must be a complete class or an unbounded array");
812 * @deprecated Deprecated in C++20.
813 * Use `is_standard_layout && is_trivial` instead.
815 // Could use is_standard_layout && is_trivial instead of the builtin.
816 template<typename _Tp>
818 _GLIBCXX20_DEPRECATED("use is_standard_layout && is_trivial instead")
820 : public integral_constant<bool, __is_pod(_Tp)>
822 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
823 "template argument must be a complete class or an unbounded array");
827 * @deprecated Deprecated in C++17, removed in C++20.
828 * The idea of a literal type isn't useful.
830 template<typename _Tp>
832 _GLIBCXX17_DEPRECATED
834 : public integral_constant<bool, __is_literal_type(_Tp)>
836 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
837 "template argument must be a complete class or an unbounded array");
841 template<typename _Tp>
843 : public integral_constant<bool, __is_empty(_Tp)>
847 template<typename _Tp>
848 struct is_polymorphic
849 : public integral_constant<bool, __is_polymorphic(_Tp)>
852#if __cplusplus >= 201402L
853#define __cpp_lib_is_final 201402L
856 template<typename _Tp>
858 : public integral_constant<bool, __is_final(_Tp)>
863 template<typename _Tp>
865 : public integral_constant<bool, __is_abstract(_Tp)>
868 /// @cond undocumented
869 template<typename _Tp,
870 bool = is_arithmetic<_Tp>::value>
871 struct __is_signed_helper
872 : public false_type { };
874 template<typename _Tp>
875 struct __is_signed_helper<_Tp, true>
876 : public integral_constant<bool, _Tp(-1) < _Tp(0)>
881 template<typename _Tp>
883 : public __is_signed_helper<_Tp>::type
887 template<typename _Tp>
889 : public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>::type
892 /// @cond undocumented
893 template<typename _Tp, typename _Up = _Tp&&>
897 template<typename _Tp>
902 template<typename _Tp>
903 auto declval() noexcept -> decltype(__declval<_Tp>(0));
906 struct remove_all_extents;
908 /// @cond undocumented
909 template<typename _Tp>
910 struct __is_array_known_bounds
914 template<typename _Tp, size_t _Size>
915 struct __is_array_known_bounds<_Tp[_Size]>
919 template<typename _Tp>
920 struct __is_array_unknown_bounds
924 template<typename _Tp>
925 struct __is_array_unknown_bounds<_Tp[]>
929 // Destructible and constructible type properties.
931 // In N3290 is_destructible does not say anything about function
932 // types and abstract types, see LWG 2049. This implementation
933 // describes function types as non-destructible and all complete
934 // object types as destructible, iff the explicit destructor
935 // call expression is wellformed.
936 struct __do_is_destructible_impl
938 template<typename _Tp, typename = decltype(declval<_Tp&>().~_Tp())>
939 static true_type __test(int);
942 static false_type __test(...);
945 template<typename _Tp>
946 struct __is_destructible_impl
947 : public __do_is_destructible_impl
949 typedef decltype(__test<_Tp>(0)) type;
952 template<typename _Tp,
953 bool = __or_<is_void<_Tp>,
954 __is_array_unknown_bounds<_Tp>,
955 is_function<_Tp>>::value,
956 bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
957 struct __is_destructible_safe;
959 template<typename _Tp>
960 struct __is_destructible_safe<_Tp, false, false>
961 : public __is_destructible_impl<typename
962 remove_all_extents<_Tp>::type>::type
965 template<typename _Tp>
966 struct __is_destructible_safe<_Tp, true, false>
967 : public false_type { };
969 template<typename _Tp>
970 struct __is_destructible_safe<_Tp, false, true>
971 : public true_type { };
975 template<typename _Tp>
976 struct is_destructible
977 : public __is_destructible_safe<_Tp>::type
979 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
980 "template argument must be a complete class or an unbounded array");
983 /// @cond undocumented
985 // is_nothrow_destructible requires that is_destructible is
986 // satisfied as well. We realize that by mimicing the
987 // implementation of is_destructible but refer to noexcept(expr)
988 // instead of decltype(expr).
989 struct __do_is_nt_destructible_impl
991 template<typename _Tp>
992 static __bool_constant<noexcept(declval<_Tp&>().~_Tp())>
996 static false_type __test(...);
999 template<typename _Tp>
1000 struct __is_nt_destructible_impl
1001 : public __do_is_nt_destructible_impl
1003 typedef decltype(__test<_Tp>(0)) type;
1006 template<typename _Tp,
1007 bool = __or_<is_void<_Tp>,
1008 __is_array_unknown_bounds<_Tp>,
1009 is_function<_Tp>>::value,
1010 bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
1011 struct __is_nt_destructible_safe;
1013 template<typename _Tp>
1014 struct __is_nt_destructible_safe<_Tp, false, false>
1015 : public __is_nt_destructible_impl<typename
1016 remove_all_extents<_Tp>::type>::type
1019 template<typename _Tp>
1020 struct __is_nt_destructible_safe<_Tp, true, false>
1021 : public false_type { };
1023 template<typename _Tp>
1024 struct __is_nt_destructible_safe<_Tp, false, true>
1025 : public true_type { };
1028 /// is_nothrow_destructible
1029 template<typename _Tp>
1030 struct is_nothrow_destructible
1031 : public __is_nt_destructible_safe<_Tp>::type
1033 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1034 "template argument must be a complete class or an unbounded array");
1037 /// @cond undocumented
1038 template<typename _Tp, typename... _Args>
1039 using __is_constructible_impl
1040 = __bool_constant<__is_constructible(_Tp, _Args...)>;
1043 /// is_constructible
1044 template<typename _Tp, typename... _Args>
1045 struct is_constructible
1046 : public __is_constructible_impl<_Tp, _Args...>
1048 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1049 "template argument must be a complete class or an unbounded array");
1052 /// is_default_constructible
1053 template<typename _Tp>
1054 struct is_default_constructible
1055 : public __is_constructible_impl<_Tp>
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, typename = void>
1063 struct __add_lvalue_reference_helper
1064 { using type = _Tp; };
1066 template<typename _Tp>
1067 struct __add_lvalue_reference_helper<_Tp, __void_t<_Tp&>>
1068 { using type = _Tp&; };
1070 template<typename _Tp>
1071 using __add_lval_ref_t = typename __add_lvalue_reference_helper<_Tp>::type;
1074 /// is_copy_constructible
1075 template<typename _Tp>
1076 struct is_copy_constructible
1077 : public __is_constructible_impl<_Tp, __add_lval_ref_t<const _Tp>>
1079 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1080 "template argument must be a complete class or an unbounded array");
1083 /// @cond undocumented
1084 template<typename _Tp, typename = void>
1085 struct __add_rvalue_reference_helper
1086 { using type = _Tp; };
1088 template<typename _Tp>
1089 struct __add_rvalue_reference_helper<_Tp, __void_t<_Tp&&>>
1090 { using type = _Tp&&; };
1092 template<typename _Tp>
1093 using __add_rval_ref_t = typename __add_rvalue_reference_helper<_Tp>::type;
1096 /// is_move_constructible
1097 template<typename _Tp>
1098 struct is_move_constructible
1099 : public __is_constructible_impl<_Tp, __add_rval_ref_t<_Tp>>
1101 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1102 "template argument must be a complete class or an unbounded array");
1105 /// @cond undocumented
1106 template<typename _Tp, typename... _Args>
1107 using __is_nothrow_constructible_impl
1108 = __bool_constant<__is_nothrow_constructible(_Tp, _Args...)>;
1111 /// is_nothrow_constructible
1112 template<typename _Tp, typename... _Args>
1113 struct is_nothrow_constructible
1114 : public __is_nothrow_constructible_impl<_Tp, _Args...>
1116 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1117 "template argument must be a complete class or an unbounded array");
1120 /// is_nothrow_default_constructible
1121 template<typename _Tp>
1122 struct is_nothrow_default_constructible
1123 : public __is_nothrow_constructible_impl<_Tp>
1125 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1126 "template argument must be a complete class or an unbounded array");
1129 /// is_nothrow_copy_constructible
1130 template<typename _Tp>
1131 struct is_nothrow_copy_constructible
1132 : public __is_nothrow_constructible_impl<_Tp, __add_lval_ref_t<const _Tp>>
1134 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1135 "template argument must be a complete class or an unbounded array");
1138 /// is_nothrow_move_constructible
1139 template<typename _Tp>
1140 struct is_nothrow_move_constructible
1141 : public __is_nothrow_constructible_impl<_Tp, __add_rval_ref_t<_Tp>>
1143 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1144 "template argument must be a complete class or an unbounded array");
1147 /// @cond undocumented
1148 template<typename _Tp, typename _Up>
1149 using __is_assignable_impl = __bool_constant<__is_assignable(_Tp, _Up)>;
1153 template<typename _Tp, typename _Up>
1154 struct is_assignable
1155 : public __is_assignable_impl<_Tp, _Up>
1157 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1158 "template argument must be a complete class or an unbounded array");
1161 /// is_copy_assignable
1162 template<typename _Tp>
1163 struct is_copy_assignable
1164 : public __is_assignable_impl<__add_lval_ref_t<_Tp>,
1165 __add_lval_ref_t<const _Tp>>
1167 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1168 "template argument must be a complete class or an unbounded array");
1171 /// is_move_assignable
1172 template<typename _Tp>
1173 struct is_move_assignable
1174 : public __is_assignable_impl<__add_lval_ref_t<_Tp>, __add_rval_ref_t<_Tp>>
1176 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1177 "template argument must be a complete class or an unbounded array");
1180 /// @cond undocumented
1181 template<typename _Tp, typename _Up>
1182 using __is_nothrow_assignable_impl
1183 = __bool_constant<__is_nothrow_assignable(_Tp, _Up)>;
1186 /// is_nothrow_assignable
1187 template<typename _Tp, typename _Up>
1188 struct is_nothrow_assignable
1189 : public __is_nothrow_assignable_impl<_Tp, _Up>
1191 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1192 "template argument must be a complete class or an unbounded array");
1195 /// is_nothrow_copy_assignable
1196 template<typename _Tp>
1197 struct is_nothrow_copy_assignable
1198 : public __is_nothrow_assignable_impl<__add_lval_ref_t<_Tp>,
1199 __add_lval_ref_t<const _Tp>>
1201 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1202 "template argument must be a complete class or an unbounded array");
1205 /// is_nothrow_move_assignable
1206 template<typename _Tp>
1207 struct is_nothrow_move_assignable
1208 : public __is_nothrow_assignable_impl<__add_lval_ref_t<_Tp>,
1209 __add_rval_ref_t<_Tp>>
1211 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1212 "template argument must be a complete class or an unbounded array");
1215 /// @cond undocumented
1216 template<typename _Tp, typename... _Args>
1217 using __is_trivially_constructible_impl
1218 = __bool_constant<__is_trivially_constructible(_Tp, _Args...)>;
1221 /// is_trivially_constructible
1222 template<typename _Tp, typename... _Args>
1223 struct is_trivially_constructible
1224 : public __is_trivially_constructible_impl<_Tp, _Args...>
1226 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1227 "template argument must be a complete class or an unbounded array");
1230 /// is_trivially_default_constructible
1231 template<typename _Tp>
1232 struct is_trivially_default_constructible
1233 : public __is_trivially_constructible_impl<_Tp>
1235 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1236 "template argument must be a complete class or an unbounded array");
1239 struct __do_is_implicitly_default_constructible_impl
1241 template <typename _Tp>
1242 static void __helper(const _Tp&);
1244 template <typename _Tp>
1245 static true_type __test(const _Tp&,
1246 decltype(__helper<const _Tp&>({}))* = 0);
1248 static false_type __test(...);
1251 template<typename _Tp>
1252 struct __is_implicitly_default_constructible_impl
1253 : public __do_is_implicitly_default_constructible_impl
1255 typedef decltype(__test(declval<_Tp>())) type;
1258 template<typename _Tp>
1259 struct __is_implicitly_default_constructible_safe
1260 : public __is_implicitly_default_constructible_impl<_Tp>::type
1263 template <typename _Tp>
1264 struct __is_implicitly_default_constructible
1265 : public __and_<__is_constructible_impl<_Tp>,
1266 __is_implicitly_default_constructible_safe<_Tp>>::type
1269 /// is_trivially_copy_constructible
1270 template<typename _Tp>
1271 struct is_trivially_copy_constructible
1272 : public __is_trivially_constructible_impl<_Tp, __add_lval_ref_t<const _Tp>>
1274 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1275 "template argument must be a complete class or an unbounded array");
1278 /// is_trivially_move_constructible
1279 template<typename _Tp>
1280 struct is_trivially_move_constructible
1281 : public __is_trivially_constructible_impl<_Tp, __add_rval_ref_t<_Tp>>
1283 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1284 "template argument must be a complete class or an unbounded array");
1287 /// @cond undocumented
1288 template<typename _Tp, typename _Up>
1289 using __is_trivially_assignable_impl
1290 = __bool_constant<__is_trivially_assignable(_Tp, _Up)>;
1293 /// is_trivially_assignable
1294 template<typename _Tp, typename _Up>
1295 struct is_trivially_assignable
1296 : public __is_trivially_assignable_impl<_Tp, _Up>
1298 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1299 "template argument must be a complete class or an unbounded array");
1302 /// is_trivially_copy_assignable
1303 template<typename _Tp>
1304 struct is_trivially_copy_assignable
1305 : public __is_trivially_assignable_impl<__add_lval_ref_t<_Tp>,
1306 __add_lval_ref_t<const _Tp>>
1308 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1309 "template argument must be a complete class or an unbounded array");
1312 /// is_trivially_move_assignable
1313 template<typename _Tp>
1314 struct is_trivially_move_assignable
1315 : public __is_trivially_assignable_impl<__add_lval_ref_t<_Tp>,
1316 __add_rval_ref_t<_Tp>>
1318 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1319 "template argument must be a complete class or an unbounded array");
1322 /// is_trivially_destructible
1323 template<typename _Tp>
1324 struct is_trivially_destructible
1325 : public __and_<__is_destructible_safe<_Tp>,
1326 __bool_constant<__has_trivial_destructor(_Tp)>>::type
1328 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1329 "template argument must be a complete class or an unbounded array");
1333 /// has_virtual_destructor
1334 template<typename _Tp>
1335 struct has_virtual_destructor
1336 : public integral_constant<bool, __has_virtual_destructor(_Tp)>
1338 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1339 "template argument must be a complete class or an unbounded array");
1343 // type property queries.
1346 template<typename _Tp>
1348 : public integral_constant<std::size_t, alignof(_Tp)>
1350 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1351 "template argument must be a complete class or an unbounded array");
1357 : public integral_constant<std::size_t, 0> { };
1359 template<typename _Tp, std::size_t _Size>
1360 struct rank<_Tp[_Size]>
1361 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1363 template<typename _Tp>
1365 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1368 template<typename, unsigned _Uint = 0>
1370 : public integral_constant<size_t, 0> { };
1372 template<typename _Tp, size_t _Size>
1373 struct extent<_Tp[_Size], 0>
1374 : public integral_constant<size_t, _Size> { };
1376 template<typename _Tp, unsigned _Uint, size_t _Size>
1377 struct extent<_Tp[_Size], _Uint>
1378 : public extent<_Tp, _Uint - 1>::type { };
1380 template<typename _Tp>
1381 struct extent<_Tp[], 0>
1382 : public integral_constant<size_t, 0> { };
1384 template<typename _Tp, unsigned _Uint>
1385 struct extent<_Tp[], _Uint>
1386 : public extent<_Tp, _Uint - 1>::type { };
1392 template<typename _Tp, typename _Up>
1394#ifdef _GLIBCXX_HAVE_BUILTIN_IS_SAME
1395 : public integral_constant<bool, __is_same(_Tp, _Up)>
1401#ifndef _GLIBCXX_HAVE_BUILTIN_IS_SAME
1402 template<typename _Tp>
1403 struct is_same<_Tp, _Tp>
1409 template<typename _Base, typename _Derived>
1411 : public integral_constant<bool, __is_base_of(_Base, _Derived)>
1414#if __has_builtin(__is_convertible)
1415 template<typename _From, typename _To>
1416 struct is_convertible
1417 : public __bool_constant<__is_convertible(_From, _To)>
1420 template<typename _From, typename _To,
1421 bool = __or_<is_void<_From>, is_function<_To>,
1422 is_array<_To>>::value>
1423 struct __is_convertible_helper
1425 typedef typename is_void<_To>::type type;
1428#pragma GCC diagnostic push
1429#pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
1430 template<typename _From, typename _To>
1431 class __is_convertible_helper<_From, _To, false>
1433 template<typename _To1>
1434 static void __test_aux(_To1) noexcept;
1436 template<typename _From1, typename _To1,
1437 typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
1441 template<typename, typename>
1446 typedef decltype(__test<_From, _To>(0)) type;
1448#pragma GCC diagnostic pop
1451 template<typename _From, typename _To>
1452 struct is_convertible
1453 : public __is_convertible_helper<_From, _To>::type
1457 // helper trait for unique_ptr<T[]>, shared_ptr<T[]>, and span<T, N>
1458 template<typename _ToElementType, typename _FromElementType>
1459 using __is_array_convertible
1460 = is_convertible<_FromElementType(*)[], _ToElementType(*)[]>;
1462#if __cplusplus >= 202002L
1463#define __cpp_lib_is_nothrow_convertible 201806L
1465#if __has_builtin(__is_nothrow_convertible)
1466 /// is_nothrow_convertible_v
1467 template<typename _From, typename _To>
1468 inline constexpr bool is_nothrow_convertible_v
1469 = __is_nothrow_convertible(_From, _To);
1471 /// is_nothrow_convertible
1472 template<typename _From, typename _To>
1473 struct is_nothrow_convertible
1474 : public bool_constant<is_nothrow_convertible_v<_From, _To>>
1477 template<typename _From, typename _To,
1478 bool = __or_<is_void<_From>, is_function<_To>,
1479 is_array<_To>>::value>
1480 struct __is_nt_convertible_helper
1484#pragma GCC diagnostic push
1485#pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
1486 template<typename _From, typename _To>
1487 class __is_nt_convertible_helper<_From, _To, false>
1489 template<typename _To1>
1490 static void __test_aux(_To1) noexcept;
1492 template<typename _From1, typename _To1>
1494 __bool_constant<noexcept(__test_aux<_To1>(std::declval<_From1>()))>
1497 template<typename, typename>
1502 using type = decltype(__test<_From, _To>(0));
1504#pragma GCC diagnostic pop
1506 /// is_nothrow_convertible
1507 template<typename _From, typename _To>
1508 struct is_nothrow_convertible
1509 : public __is_nt_convertible_helper<_From, _To>::type
1512 /// is_nothrow_convertible_v
1513 template<typename _From, typename _To>
1514 inline constexpr bool is_nothrow_convertible_v
1515 = is_nothrow_convertible<_From, _To>::value;
1519 // Const-volatile modifications.
1522 template<typename _Tp>
1524 { typedef _Tp type; };
1526 template<typename _Tp>
1527 struct remove_const<_Tp const>
1528 { typedef _Tp type; };
1531 template<typename _Tp>
1532 struct remove_volatile
1533 { typedef _Tp type; };
1535 template<typename _Tp>
1536 struct remove_volatile<_Tp volatile>
1537 { typedef _Tp type; };
1540#if __has_builtin(__remove_cv)
1541 template<typename _Tp>
1543 { using type = __remove_cv(_Tp); };
1545 template<typename _Tp>
1547 { using type = _Tp; };
1549 template<typename _Tp>
1550 struct remove_cv<const _Tp>
1551 { using type = _Tp; };
1553 template<typename _Tp>
1554 struct remove_cv<volatile _Tp>
1555 { using type = _Tp; };
1557 template<typename _Tp>
1558 struct remove_cv<const volatile _Tp>
1559 { using type = _Tp; };
1563 template<typename _Tp>
1565 { using type = _Tp const; };
1568 template<typename _Tp>
1570 { using type = _Tp volatile; };
1573 template<typename _Tp>
1575 { using type = _Tp const volatile; };
1577#if __cplusplus > 201103L
1579#define __cpp_lib_transformation_trait_aliases 201304L
1581 /// Alias template for remove_const
1582 template<typename _Tp>
1583 using remove_const_t = typename remove_const<_Tp>::type;
1585 /// Alias template for remove_volatile
1586 template<typename _Tp>
1587 using remove_volatile_t = typename remove_volatile<_Tp>::type;
1589 /// Alias template for remove_cv
1590 template<typename _Tp>
1591 using remove_cv_t = typename remove_cv<_Tp>::type;
1593 /// Alias template for add_const
1594 template<typename _Tp>
1595 using add_const_t = typename add_const<_Tp>::type;
1597 /// Alias template for add_volatile
1598 template<typename _Tp>
1599 using add_volatile_t = typename add_volatile<_Tp>::type;
1601 /// Alias template for add_cv
1602 template<typename _Tp>
1603 using add_cv_t = typename add_cv<_Tp>::type;
1606 // Reference transformations.
1608 /// remove_reference
1609#if __has_builtin(__remove_reference)
1610 template<typename _Tp>
1611 struct remove_reference
1612 { using type = __remove_reference(_Tp); };
1614 template<typename _Tp>
1615 struct remove_reference
1616 { using type = _Tp; };
1618 template<typename _Tp>
1619 struct remove_reference<_Tp&>
1620 { using type = _Tp; };
1622 template<typename _Tp>
1623 struct remove_reference<_Tp&&>
1624 { using type = _Tp; };
1627 /// add_lvalue_reference
1628 template<typename _Tp>
1629 struct add_lvalue_reference
1630 { using type = __add_lval_ref_t<_Tp>; };
1632 /// add_rvalue_reference
1633 template<typename _Tp>
1634 struct add_rvalue_reference
1635 { using type = __add_rval_ref_t<_Tp>; };
1637#if __cplusplus > 201103L
1638 /// Alias template for remove_reference
1639 template<typename _Tp>
1640 using remove_reference_t = typename remove_reference<_Tp>::type;
1642 /// Alias template for add_lvalue_reference
1643 template<typename _Tp>
1644 using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
1646 /// Alias template for add_rvalue_reference
1647 template<typename _Tp>
1648 using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
1651 // Sign modifications.
1653 /// @cond undocumented
1655 // Utility for constructing identically cv-qualified types.
1656 template<typename _Unqualified, bool _IsConst, bool _IsVol>
1657 struct __cv_selector;
1659 template<typename _Unqualified>
1660 struct __cv_selector<_Unqualified, false, false>
1661 { typedef _Unqualified __type; };
1663 template<typename _Unqualified>
1664 struct __cv_selector<_Unqualified, false, true>
1665 { typedef volatile _Unqualified __type; };
1667 template<typename _Unqualified>
1668 struct __cv_selector<_Unqualified, true, false>
1669 { typedef const _Unqualified __type; };
1671 template<typename _Unqualified>
1672 struct __cv_selector<_Unqualified, true, true>
1673 { typedef const volatile _Unqualified __type; };
1675 template<typename _Qualified, typename _Unqualified,
1676 bool _IsConst = is_const<_Qualified>::value,
1677 bool _IsVol = is_volatile<_Qualified>::value>
1678 class __match_cv_qualifiers
1680 typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
1683 typedef typename __match::__type __type;
1686 // Utility for finding the unsigned versions of signed integral types.
1687 template<typename _Tp>
1688 struct __make_unsigned
1689 { typedef _Tp __type; };
1692 struct __make_unsigned<char>
1693 { typedef unsigned char __type; };
1696 struct __make_unsigned<signed char>
1697 { typedef unsigned char __type; };
1700 struct __make_unsigned<short>
1701 { typedef unsigned short __type; };
1704 struct __make_unsigned<int>
1705 { typedef unsigned int __type; };
1708 struct __make_unsigned<long>
1709 { typedef unsigned long __type; };
1712 struct __make_unsigned<long long>
1713 { typedef unsigned long long __type; };
1715#if defined(__GLIBCXX_TYPE_INT_N_0)
1718 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_0>
1719 { typedef unsigned __GLIBCXX_TYPE_INT_N_0 __type; };
1721#if defined(__GLIBCXX_TYPE_INT_N_1)
1724 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_1>
1725 { typedef unsigned __GLIBCXX_TYPE_INT_N_1 __type; };
1727#if defined(__GLIBCXX_TYPE_INT_N_2)
1730 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_2>
1731 { typedef unsigned __GLIBCXX_TYPE_INT_N_2 __type; };
1733#if defined(__GLIBCXX_TYPE_INT_N_3)
1736 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_3>
1737 { typedef unsigned __GLIBCXX_TYPE_INT_N_3 __type; };
1740 // Select between integral and enum: not possible to be both.
1741 template<typename _Tp,
1742 bool _IsInt = is_integral<_Tp>::value,
1743 bool _IsEnum = is_enum<_Tp>::value>
1744 class __make_unsigned_selector;
1746 template<typename _Tp>
1747 class __make_unsigned_selector<_Tp, true, false>
1749 using __unsigned_type
1750 = typename __make_unsigned<__remove_cv_t<_Tp>>::__type;
1754 = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1757 class __make_unsigned_selector_base
1760 template<typename...> struct _List { };
1762 template<typename _Tp, typename... _Up>
1763 struct _List<_Tp, _Up...> : _List<_Up...>
1764 { static constexpr size_t __size = sizeof(_Tp); };
1766 template<size_t _Sz, typename _Tp, bool = (_Sz <= _Tp::__size)>
1769 template<size_t _Sz, typename _Uint, typename... _UInts>
1770 struct __select<_Sz, _List<_Uint, _UInts...>, true>
1771 { using __type = _Uint; };
1773 template<size_t _Sz, typename _Uint, typename... _UInts>
1774 struct __select<_Sz, _List<_Uint, _UInts...>, false>
1775 : __select<_Sz, _List<_UInts...>>
1779 // Choose unsigned integer type with the smallest rank and same size as _Tp
1780 template<typename _Tp>
1781 class __make_unsigned_selector<_Tp, false, true>
1782 : __make_unsigned_selector_base
1784 // With -fshort-enums, an enum may be as small as a char.
1785 using _UInts = _List<unsigned char, unsigned short, unsigned int,
1786 unsigned long, unsigned long long>;
1788 using __unsigned_type = typename __select<sizeof(_Tp), _UInts>::__type;
1792 = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1795 // wchar_t, char8_t, char16_t and char32_t are integral types but are
1796 // neither signed integer types nor unsigned integer types, so must be
1797 // transformed to the unsigned integer type with the smallest rank.
1798 // Use the partial specialization for enumeration types to do that.
1800 struct __make_unsigned<wchar_t>
1803 = typename __make_unsigned_selector<wchar_t, false, true>::__type;
1806#ifdef _GLIBCXX_USE_CHAR8_T
1808 struct __make_unsigned<char8_t>
1811 = typename __make_unsigned_selector<char8_t, false, true>::__type;
1816 struct __make_unsigned<char16_t>
1819 = typename __make_unsigned_selector<char16_t, false, true>::__type;
1823 struct __make_unsigned<char32_t>
1826 = typename __make_unsigned_selector<char32_t, false, true>::__type;
1830 // Given an integral/enum type, return the corresponding unsigned
1832 // Primary template.
1834 template<typename _Tp>
1835 struct make_unsigned
1836 { typedef typename __make_unsigned_selector<_Tp>::__type type; };
1838 // Integral, but don't define.
1839 template<> struct make_unsigned<bool>;
1840 template<> struct make_unsigned<bool const>;
1841 template<> struct make_unsigned<bool volatile>;
1842 template<> struct make_unsigned<bool const volatile>;
1844 /// @cond undocumented
1846 // Utility for finding the signed versions of unsigned integral types.
1847 template<typename _Tp>
1848 struct __make_signed
1849 { typedef _Tp __type; };
1852 struct __make_signed<char>
1853 { typedef signed char __type; };
1856 struct __make_signed<unsigned char>
1857 { typedef signed char __type; };
1860 struct __make_signed<unsigned short>
1861 { typedef signed short __type; };
1864 struct __make_signed<unsigned int>
1865 { typedef signed int __type; };
1868 struct __make_signed<unsigned long>
1869 { typedef signed long __type; };
1872 struct __make_signed<unsigned long long>
1873 { typedef signed long long __type; };
1875#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)
1884 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_1>
1885 { typedef __GLIBCXX_TYPE_INT_N_1 __type; };
1887#if defined(__GLIBCXX_TYPE_INT_N_2)
1890 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_2>
1891 { typedef __GLIBCXX_TYPE_INT_N_2 __type; };
1893#if defined(__GLIBCXX_TYPE_INT_N_3)
1896 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_3>
1897 { typedef __GLIBCXX_TYPE_INT_N_3 __type; };
1900 // Select between integral and enum: not possible to be both.
1901 template<typename _Tp,
1902 bool _IsInt = is_integral<_Tp>::value,
1903 bool _IsEnum = is_enum<_Tp>::value>
1904 class __make_signed_selector;
1906 template<typename _Tp>
1907 class __make_signed_selector<_Tp, true, false>
1910 = typename __make_signed<__remove_cv_t<_Tp>>::__type;
1914 = typename __match_cv_qualifiers<_Tp, __signed_type>::__type;
1917 // Choose signed integer type with the smallest rank and same size as _Tp
1918 template<typename _Tp>
1919 class __make_signed_selector<_Tp, false, true>
1921 typedef typename __make_unsigned_selector<_Tp>::__type __unsigned_type;
1924 typedef typename __make_signed_selector<__unsigned_type>::__type __type;
1927 // wchar_t, char16_t and char32_t are integral types but are neither
1928 // signed integer types nor unsigned integer types, so must be
1929 // transformed to the signed integer type with the smallest rank.
1930 // Use the partial specialization for enumeration types to do that.
1932 struct __make_signed<wchar_t>
1935 = typename __make_signed_selector<wchar_t, false, true>::__type;
1938#if defined(_GLIBCXX_USE_CHAR8_T)
1940 struct __make_signed<char8_t>
1943 = typename __make_signed_selector<char8_t, false, true>::__type;
1948 struct __make_signed<char16_t>
1951 = typename __make_signed_selector<char16_t, false, true>::__type;
1955 struct __make_signed<char32_t>
1958 = typename __make_signed_selector<char32_t, false, true>::__type;
1962 // Given an integral/enum type, return the corresponding signed
1964 // Primary template.
1966 template<typename _Tp>
1968 { typedef typename __make_signed_selector<_Tp>::__type type; };
1970 // Integral, but don't define.
1971 template<> struct make_signed<bool>;
1972 template<> struct make_signed<bool const>;
1973 template<> struct make_signed<bool volatile>;
1974 template<> struct make_signed<bool const volatile>;
1976#if __cplusplus > 201103L
1977 /// Alias template for make_signed
1978 template<typename _Tp>
1979 using make_signed_t = typename make_signed<_Tp>::type;
1981 /// Alias template for make_unsigned
1982 template<typename _Tp>
1983 using make_unsigned_t = typename make_unsigned<_Tp>::type;
1986 // Array modifications.
1989 template<typename _Tp>
1990 struct remove_extent
1991 { typedef _Tp type; };
1993 template<typename _Tp, std::size_t _Size>
1994 struct remove_extent<_Tp[_Size]>
1995 { typedef _Tp type; };
1997 template<typename _Tp>
1998 struct remove_extent<_Tp[]>
1999 { typedef _Tp type; };
2001 /// remove_all_extents
2002 template<typename _Tp>
2003 struct remove_all_extents
2004 { typedef _Tp type; };
2006 template<typename _Tp, std::size_t _Size>
2007 struct remove_all_extents<_Tp[_Size]>
2008 { typedef typename remove_all_extents<_Tp>::type type; };
2010 template<typename _Tp>
2011 struct remove_all_extents<_Tp[]>
2012 { typedef typename remove_all_extents<_Tp>::type type; };
2014#if __cplusplus > 201103L
2015 /// Alias template for remove_extent
2016 template<typename _Tp>
2017 using remove_extent_t = typename remove_extent<_Tp>::type;
2019 /// Alias template for remove_all_extents
2020 template<typename _Tp>
2021 using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
2024 // Pointer modifications.
2026 template<typename _Tp, typename>
2027 struct __remove_pointer_helper
2028 { typedef _Tp type; };
2030 template<typename _Tp, typename _Up>
2031 struct __remove_pointer_helper<_Tp, _Up*>
2032 { typedef _Up type; };
2035 template<typename _Tp>
2036 struct remove_pointer
2037 : public __remove_pointer_helper<_Tp, __remove_cv_t<_Tp>>
2040 template<typename _Tp, typename = void>
2041 struct __add_pointer_helper
2042 { using type = _Tp; };
2044 template<typename _Tp>
2045 struct __add_pointer_helper<_Tp, __void_t<_Tp*>>
2046 { using type = _Tp*; };
2049 template<typename _Tp>
2051 : public __add_pointer_helper<_Tp>
2054 template<typename _Tp>
2055 struct add_pointer<_Tp&>
2056 { using type = _Tp*; };
2058 template<typename _Tp>
2059 struct add_pointer<_Tp&&>
2060 { using type = _Tp*; };
2062#if __cplusplus > 201103L
2063 /// Alias template for remove_pointer
2064 template<typename _Tp>
2065 using remove_pointer_t = typename remove_pointer<_Tp>::type;
2067 /// Alias template for add_pointer
2068 template<typename _Tp>
2069 using add_pointer_t = typename add_pointer<_Tp>::type;
2072 template<std::size_t _Len>
2073 struct __aligned_storage_msa
2077 unsigned char __data[_Len];
2078 struct __attribute__((__aligned__)) { } __align;
2083 * @brief Alignment type.
2085 * The value of _Align is a default-alignment which shall be the
2086 * most stringent alignment requirement for any C++ object type
2087 * whose size is no greater than _Len (3.9). The member typedef
2088 * type shall be a POD type suitable for use as uninitialized
2089 * storage for any object whose size is at most _Len and whose
2090 * alignment is a divisor of _Align.
2092 template<std::size_t _Len, std::size_t _Align =
2093 __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2094 struct aligned_storage
2098 unsigned char __data[_Len];
2099 struct __attribute__((__aligned__((_Align)))) { } __align;
2103 template <typename... _Types>
2104 struct __strictest_alignment
2106 static const size_t _S_alignment = 0;
2107 static const size_t _S_size = 0;
2110 template <typename _Tp, typename... _Types>
2111 struct __strictest_alignment<_Tp, _Types...>
2113 static const size_t _S_alignment =
2114 alignof(_Tp) > __strictest_alignment<_Types...>::_S_alignment
2115 ? alignof(_Tp) : __strictest_alignment<_Types...>::_S_alignment;
2116 static const size_t _S_size =
2117 sizeof(_Tp) > __strictest_alignment<_Types...>::_S_size
2118 ? sizeof(_Tp) : __strictest_alignment<_Types...>::_S_size;
2122 * @brief Provide aligned storage for types.
2124 * [meta.trans.other]
2126 * Provides aligned storage for any of the provided types of at
2129 * @see aligned_storage
2131 template <size_t _Len, typename... _Types>
2132 struct aligned_union
2135 static_assert(sizeof...(_Types) != 0, "At least one type is required");
2137 using __strictest = __strictest_alignment<_Types...>;
2138 static const size_t _S_len = _Len > __strictest::_S_size
2139 ? _Len : __strictest::_S_size;
2141 /// The value of the strictest alignment of _Types.
2142 static const size_t alignment_value = __strictest::_S_alignment;
2144 typedef typename aligned_storage<_S_len, alignment_value>::type type;
2147 template <size_t _Len, typename... _Types>
2148 const size_t aligned_union<_Len, _Types...>::alignment_value;
2150 /// @cond undocumented
2152 // Decay trait for arrays and functions, used for perfect forwarding
2153 // in make_pair, make_tuple, etc.
2154 template<typename _Up>
2155 struct __decay_selector
2156 : __conditional_t<is_const<const _Up>::value, // false for functions
2157 remove_cv<_Up>, // N.B. DR 705.
2158 add_pointer<_Up>> // function decays to pointer
2161 template<typename _Up, size_t _Nm>
2162 struct __decay_selector<_Up[_Nm]>
2163 { using type = _Up*; };
2165 template<typename _Up>
2166 struct __decay_selector<_Up[]>
2167 { using type = _Up*; };
2172 template<typename _Tp>
2174 { using type = typename __decay_selector<_Tp>::type; };
2176 template<typename _Tp>
2178 { using type = typename __decay_selector<_Tp>::type; };
2180 template<typename _Tp>
2182 { using type = typename __decay_selector<_Tp>::type; };
2184 /// @cond undocumented
2186 // Helper which adds a reference to a type when given a reference_wrapper
2187 template<typename _Tp>
2188 struct __strip_reference_wrapper
2193 template<typename _Tp>
2194 struct __strip_reference_wrapper<reference_wrapper<_Tp> >
2196 typedef _Tp& __type;
2199 // __decay_t (std::decay_t for C++11).
2200 template<typename _Tp>
2201 using __decay_t = typename decay<_Tp>::type;
2203 template<typename _Tp>
2204 using __decay_and_strip = __strip_reference_wrapper<__decay_t<_Tp>>;
2207 /// @cond undocumented
2209 // Helper for SFINAE constraints
2210 template<typename... _Cond>
2211 using _Require = __enable_if_t<__and_<_Cond...>::value>;
2213 // __remove_cvref_t (std::remove_cvref_t for C++11).
2214 template<typename _Tp>
2215 using __remove_cvref_t
2216 = typename remove_cv<typename remove_reference<_Tp>::type>::type;
2219 // Primary template.
2220 /// Define a member typedef @c type to one of two argument types.
2221 template<bool _Cond, typename _Iftrue, typename _Iffalse>
2223 { typedef _Iftrue type; };
2225 // Partial specialization for false.
2226 template<typename _Iftrue, typename _Iffalse>
2227 struct conditional<false, _Iftrue, _Iffalse>
2228 { typedef _Iffalse type; };
2231 template<typename... _Tp>
2234 // Sfinae-friendly common_type implementation:
2236 /// @cond undocumented
2238 // For several sfinae-friendly trait implementations we transport both the
2239 // result information (as the member type) and the failure information (no
2240 // member type). This is very similar to std::enable_if, but we cannot use
2241 // that, because we need to derive from them as an implementation detail.
2243 template<typename _Tp>
2244 struct __success_type
2245 { typedef _Tp type; };
2247 struct __failure_type
2250 struct __do_common_type_impl
2252 template<typename _Tp, typename _Up>
2254 = decltype(true ? std::declval<_Tp>() : std::declval<_Up>());
2256 // if decay_t<decltype(false ? declval<D1>() : declval<D2>())>
2257 // denotes a valid type, let C denote that type.
2258 template<typename _Tp, typename _Up>
2259 static __success_type<__decay_t<__cond_t<_Tp, _Up>>>
2262#if __cplusplus > 201703L
2263 // Otherwise, if COND-RES(CREF(D1), CREF(D2)) denotes a type,
2264 // let C denote the type decay_t<COND-RES(CREF(D1), CREF(D2))>.
2265 template<typename _Tp, typename _Up>
2266 static __success_type<__remove_cvref_t<__cond_t<const _Tp&, const _Up&>>>
2270 template<typename, typename>
2271 static __failure_type
2274 template<typename _Tp, typename _Up>
2275 static decltype(_S_test_2<_Tp, _Up>(0))
2279 // If sizeof...(T) is zero, there shall be no member type.
2281 struct common_type<>
2284 // If sizeof...(T) is one, the same type, if any, as common_type_t<T0, T0>.
2285 template<typename _Tp0>
2286 struct common_type<_Tp0>
2287 : public common_type<_Tp0, _Tp0>
2290 // If sizeof...(T) is two, ...
2291 template<typename _Tp1, typename _Tp2,
2292 typename _Dp1 = __decay_t<_Tp1>, typename _Dp2 = __decay_t<_Tp2>>
2293 struct __common_type_impl
2295 // If is_same_v<T1, D1> is false or is_same_v<T2, D2> is false,
2296 // let C denote the same type, if any, as common_type_t<D1, D2>.
2297 using type = common_type<_Dp1, _Dp2>;
2300 template<typename _Tp1, typename _Tp2>
2301 struct __common_type_impl<_Tp1, _Tp2, _Tp1, _Tp2>
2302 : private __do_common_type_impl
2304 // Otherwise, if decay_t<decltype(false ? declval<D1>() : declval<D2>())>
2305 // denotes a valid type, let C denote that type.
2306 using type = decltype(_S_test<_Tp1, _Tp2>(0));
2309 // If sizeof...(T) is two, ...
2310 template<typename _Tp1, typename _Tp2>
2311 struct common_type<_Tp1, _Tp2>
2312 : public __common_type_impl<_Tp1, _Tp2>::type
2315 template<typename...>
2316 struct __common_type_pack
2319 template<typename, typename, typename = void>
2320 struct __common_type_fold;
2322 // If sizeof...(T) is greater than two, ...
2323 template<typename _Tp1, typename _Tp2, typename... _Rp>
2324 struct common_type<_Tp1, _Tp2, _Rp...>
2325 : public __common_type_fold<common_type<_Tp1, _Tp2>,
2326 __common_type_pack<_Rp...>>
2329 // Let C denote the same type, if any, as common_type_t<T1, T2>.
2330 // If there is such a type C, type shall denote the same type, if any,
2331 // as common_type_t<C, R...>.
2332 template<typename _CTp, typename... _Rp>
2333 struct __common_type_fold<_CTp, __common_type_pack<_Rp...>,
2334 __void_t<typename _CTp::type>>
2335 : public common_type<typename _CTp::type, _Rp...>
2338 // Otherwise, there shall be no member type.
2339 template<typename _CTp, typename _Rp>
2340 struct __common_type_fold<_CTp, _Rp, void>
2343 template<typename _Tp, bool = is_enum<_Tp>::value>
2344 struct __underlying_type_impl
2346 using type = __underlying_type(_Tp);
2349 template<typename _Tp>
2350 struct __underlying_type_impl<_Tp, false>
2354 /// The underlying type of an enum.
2355 template<typename _Tp>
2356 struct underlying_type
2357 : public __underlying_type_impl<_Tp>
2360 /// @cond undocumented
2361 template<typename _Tp>
2362 struct __declval_protector
2364 static const bool __stop = false;
2368 /** Utility to simplify expressions used in unevaluated operands
2370 * @ingroup utilities
2372 template<typename _Tp>
2373 auto declval() noexcept -> decltype(__declval<_Tp>(0))
2375 static_assert(__declval_protector<_Tp>::__stop,
2376 "declval() must not be used!");
2377 return __declval<_Tp>(0);
2381 template<typename _Signature>
2384 // Sfinae-friendly result_of implementation:
2386#define __cpp_lib_result_of_sfinae 201210L
2388 /// @cond undocumented
2389 struct __invoke_memfun_ref { };
2390 struct __invoke_memfun_deref { };
2391 struct __invoke_memobj_ref { };
2392 struct __invoke_memobj_deref { };
2393 struct __invoke_other { };
2395 // Associate a tag type with a specialization of __success_type.
2396 template<typename _Tp, typename _Tag>
2397 struct __result_of_success : __success_type<_Tp>
2398 { using __invoke_type = _Tag; };
2400 // [func.require] paragraph 1 bullet 1:
2401 struct __result_of_memfun_ref_impl
2403 template<typename _Fp, typename _Tp1, typename... _Args>
2404 static __result_of_success<decltype(
2405 (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
2406 ), __invoke_memfun_ref> _S_test(int);
2408 template<typename...>
2409 static __failure_type _S_test(...);
2412 template<typename _MemPtr, typename _Arg, typename... _Args>
2413 struct __result_of_memfun_ref
2414 : private __result_of_memfun_ref_impl
2416 typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2419 // [func.require] paragraph 1 bullet 2:
2420 struct __result_of_memfun_deref_impl
2422 template<typename _Fp, typename _Tp1, typename... _Args>
2423 static __result_of_success<decltype(
2424 ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
2425 ), __invoke_memfun_deref> _S_test(int);
2427 template<typename...>
2428 static __failure_type _S_test(...);
2431 template<typename _MemPtr, typename _Arg, typename... _Args>
2432 struct __result_of_memfun_deref
2433 : private __result_of_memfun_deref_impl
2435 typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2438 // [func.require] paragraph 1 bullet 3:
2439 struct __result_of_memobj_ref_impl
2441 template<typename _Fp, typename _Tp1>
2442 static __result_of_success<decltype(
2443 std::declval<_Tp1>().*std::declval<_Fp>()
2444 ), __invoke_memobj_ref> _S_test(int);
2446 template<typename, typename>
2447 static __failure_type _S_test(...);
2450 template<typename _MemPtr, typename _Arg>
2451 struct __result_of_memobj_ref
2452 : private __result_of_memobj_ref_impl
2454 typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2457 // [func.require] paragraph 1 bullet 4:
2458 struct __result_of_memobj_deref_impl
2460 template<typename _Fp, typename _Tp1>
2461 static __result_of_success<decltype(
2462 (*std::declval<_Tp1>()).*std::declval<_Fp>()
2463 ), __invoke_memobj_deref> _S_test(int);
2465 template<typename, typename>
2466 static __failure_type _S_test(...);
2469 template<typename _MemPtr, typename _Arg>
2470 struct __result_of_memobj_deref
2471 : private __result_of_memobj_deref_impl
2473 typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2476 template<typename _MemPtr, typename _Arg>
2477 struct __result_of_memobj;
2479 template<typename _Res, typename _Class, typename _Arg>
2480 struct __result_of_memobj<_Res _Class::*, _Arg>
2482 typedef __remove_cvref_t<_Arg> _Argval;
2483 typedef _Res _Class::* _MemPtr;
2484 typedef typename __conditional_t<__or_<is_same<_Argval, _Class>,
2485 is_base_of<_Class, _Argval>>::value,
2486 __result_of_memobj_ref<_MemPtr, _Arg>,
2487 __result_of_memobj_deref<_MemPtr, _Arg>
2491 template<typename _MemPtr, typename _Arg, typename... _Args>
2492 struct __result_of_memfun;
2494 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2495 struct __result_of_memfun<_Res _Class::*, _Arg, _Args...>
2497 typedef typename remove_reference<_Arg>::type _Argval;
2498 typedef _Res _Class::* _MemPtr;
2499 typedef typename __conditional_t<is_base_of<_Class, _Argval>::value,
2500 __result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
2501 __result_of_memfun_deref<_MemPtr, _Arg, _Args...>
2505 // _GLIBCXX_RESOLVE_LIB_DEFECTS
2506 // 2219. INVOKE-ing a pointer to member with a reference_wrapper
2507 // as the object expression
2509 // Used by result_of, invoke etc. to unwrap a reference_wrapper.
2510 template<typename _Tp, typename _Up = __remove_cvref_t<_Tp>>
2516 template<typename _Tp, typename _Up>
2517 struct __inv_unwrap<_Tp, reference_wrapper<_Up>>
2522 template<bool, bool, typename _Functor, typename... _ArgTypes>
2523 struct __result_of_impl
2525 typedef __failure_type type;
2528 template<typename _MemPtr, typename _Arg>
2529 struct __result_of_impl<true, false, _MemPtr, _Arg>
2530 : public __result_of_memobj<__decay_t<_MemPtr>,
2531 typename __inv_unwrap<_Arg>::type>
2534 template<typename _MemPtr, typename _Arg, typename... _Args>
2535 struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
2536 : public __result_of_memfun<__decay_t<_MemPtr>,
2537 typename __inv_unwrap<_Arg>::type, _Args...>
2540 // [func.require] paragraph 1 bullet 5:
2541 struct __result_of_other_impl
2543 template<typename _Fn, typename... _Args>
2544 static __result_of_success<decltype(
2545 std::declval<_Fn>()(std::declval<_Args>()...)
2546 ), __invoke_other> _S_test(int);
2548 template<typename...>
2549 static __failure_type _S_test(...);
2552 template<typename _Functor, typename... _ArgTypes>
2553 struct __result_of_impl<false, false, _Functor, _ArgTypes...>
2554 : private __result_of_other_impl
2556 typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type;
2559 // __invoke_result (std::invoke_result for C++11)
2560 template<typename _Functor, typename... _ArgTypes>
2561 struct __invoke_result
2562 : public __result_of_impl<
2563 is_member_object_pointer<
2564 typename remove_reference<_Functor>::type
2566 is_member_function_pointer<
2567 typename remove_reference<_Functor>::type
2569 _Functor, _ArgTypes...
2574 template<typename _Functor, typename... _ArgTypes>
2575 struct result_of<_Functor(_ArgTypes...)>
2576 : public __invoke_result<_Functor, _ArgTypes...>
2577 { } _GLIBCXX17_DEPRECATED_SUGGEST("std::invoke_result");
2579#if __cplusplus >= 201402L
2580 /// Alias template for aligned_storage
2581 template<size_t _Len, size_t _Align =
2582 __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2583 using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
2585 template <size_t _Len, typename... _Types>
2586 using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
2588 /// Alias template for decay
2589 template<typename _Tp>
2590 using decay_t = typename decay<_Tp>::type;
2592 /// Alias template for enable_if
2593 template<bool _Cond, typename _Tp = void>
2594 using enable_if_t = typename enable_if<_Cond, _Tp>::type;
2596 /// Alias template for conditional
2597 template<bool _Cond, typename _Iftrue, typename _Iffalse>
2598 using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
2600 /// Alias template for common_type
2601 template<typename... _Tp>
2602 using common_type_t = typename common_type<_Tp...>::type;
2604 /// Alias template for underlying_type
2605 template<typename _Tp>
2606 using underlying_type_t = typename underlying_type<_Tp>::type;
2608 /// Alias template for result_of
2609 template<typename _Tp>
2610 using result_of_t = typename result_of<_Tp>::type;
2613#if __cplusplus >= 201703L || !defined(__STRICT_ANSI__) // c++17 or gnu++11
2614#define __cpp_lib_void_t 201411L
2615 /// A metafunction that always yields void, used for detecting valid types.
2616 template<typename...> using void_t = void;
2619 /// @cond undocumented
2622 // Detect whether _Op<_Args...> is a valid type, use default _Def if not.
2625 // Implementation of the detection idiom (negative case).
2626 template<typename _Def, template<typename...> class _Op, typename... _Args>
2627 struct __detected_or
2630 using __is_detected = false_type;
2633 // Implementation of the detection idiom (positive case).
2634 template<typename _Def, template<typename...> class _Op, typename... _Args>
2635 requires requires { typename _Op<_Args...>; }
2636 struct __detected_or<_Def, _Op, _Args...>
2638 using type = _Op<_Args...>;
2639 using __is_detected = true_type;
2642 /// Implementation of the detection idiom (negative case).
2643 template<typename _Default, typename _AlwaysVoid,
2644 template<typename...> class _Op, typename... _Args>
2647 using type = _Default;
2648 using __is_detected = false_type;
2651 /// Implementation of the detection idiom (positive case).
2652 template<typename _Default, template<typename...> class _Op,
2654 struct __detector<_Default, __void_t<_Op<_Args...>>, _Op, _Args...>
2656 using type = _Op<_Args...>;
2657 using __is_detected = true_type;
2660 template<typename _Default, template<typename...> class _Op,
2662 using __detected_or = __detector<_Default, void, _Op, _Args...>;
2663#endif // __cpp_concepts
2665 // _Op<_Args...> if that is a valid type, otherwise _Default.
2666 template<typename _Default, template<typename...> class _Op,
2668 using __detected_or_t
2669 = typename __detected_or<_Default, _Op, _Args...>::type;
2672 * Use SFINAE to determine if the type _Tp has a publicly-accessible
2673 * member type _NTYPE.
2675#define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
2676 template<typename _Tp, typename = __void_t<>> \
2677 struct __has_##_NTYPE \
2680 template<typename _Tp> \
2681 struct __has_##_NTYPE<_Tp, __void_t<typename _Tp::_NTYPE>> \
2685 template <typename _Tp>
2686 struct __is_swappable;
2688 template <typename _Tp>
2689 struct __is_nothrow_swappable;
2692 struct __is_tuple_like_impl : false_type
2695 // Internal type trait that allows us to sfinae-protect tuple_cat.
2696 template<typename _Tp>
2697 struct __is_tuple_like
2698 : public __is_tuple_like_impl<__remove_cvref_t<_Tp>>::type
2702 template<typename _Tp>
2703 _GLIBCXX20_CONSTEXPR
2705 _Require<__not_<__is_tuple_like<_Tp>>,
2706 is_move_constructible<_Tp>,
2707 is_move_assignable<_Tp>>
2709 noexcept(__and_<is_nothrow_move_constructible<_Tp>,
2710 is_nothrow_move_assignable<_Tp>>::value);
2712 template<typename _Tp, size_t _Nm>
2713 _GLIBCXX20_CONSTEXPR
2715 __enable_if_t<__is_swappable<_Tp>::value>
2716 swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
2717 noexcept(__is_nothrow_swappable<_Tp>::value);
2719 /// @cond undocumented
2720 namespace __swappable_details {
2723 struct __do_is_swappable_impl
2725 template<typename _Tp, typename
2726 = decltype(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))>
2727 static true_type __test(int);
2730 static false_type __test(...);
2733 struct __do_is_nothrow_swappable_impl
2735 template<typename _Tp>
2736 static __bool_constant<
2737 noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))
2741 static false_type __test(...);
2744 } // namespace __swappable_details
2746 template<typename _Tp>
2747 struct __is_swappable_impl
2748 : public __swappable_details::__do_is_swappable_impl
2750 typedef decltype(__test<_Tp>(0)) type;
2753 template<typename _Tp>
2754 struct __is_nothrow_swappable_impl
2755 : public __swappable_details::__do_is_nothrow_swappable_impl
2757 typedef decltype(__test<_Tp>(0)) type;
2760 template<typename _Tp>
2761 struct __is_swappable
2762 : public __is_swappable_impl<_Tp>::type
2765 template<typename _Tp>
2766 struct __is_nothrow_swappable
2767 : public __is_nothrow_swappable_impl<_Tp>::type
2771#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
2772#define __cpp_lib_is_swappable 201603L
2773 /// Metafunctions used for detecting swappable types: p0185r1
2776 template<typename _Tp>
2778 : public __is_swappable_impl<_Tp>::type
2780 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2781 "template argument must be a complete class or an unbounded array");
2784 /// is_nothrow_swappable
2785 template<typename _Tp>
2786 struct is_nothrow_swappable
2787 : public __is_nothrow_swappable_impl<_Tp>::type
2789 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2790 "template argument must be a complete class or an unbounded array");
2793#if __cplusplus >= 201402L
2795 template<typename _Tp>
2796 _GLIBCXX17_INLINE constexpr bool is_swappable_v =
2797 is_swappable<_Tp>::value;
2799 /// is_nothrow_swappable_v
2800 template<typename _Tp>
2801 _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_v =
2802 is_nothrow_swappable<_Tp>::value;
2803#endif // __cplusplus >= 201402L
2805 /// @cond undocumented
2806 namespace __swappable_with_details {
2809 struct __do_is_swappable_with_impl
2811 template<typename _Tp, typename _Up, typename
2812 = decltype(swap(std::declval<_Tp>(), std::declval<_Up>())),
2814 = decltype(swap(std::declval<_Up>(), std::declval<_Tp>()))>
2815 static true_type __test(int);
2817 template<typename, typename>
2818 static false_type __test(...);
2821 struct __do_is_nothrow_swappable_with_impl
2823 template<typename _Tp, typename _Up>
2824 static __bool_constant<
2825 noexcept(swap(std::declval<_Tp>(), std::declval<_Up>()))
2827 noexcept(swap(std::declval<_Up>(), std::declval<_Tp>()))
2830 template<typename, typename>
2831 static false_type __test(...);
2834 } // namespace __swappable_with_details
2836 template<typename _Tp, typename _Up>
2837 struct __is_swappable_with_impl
2838 : public __swappable_with_details::__do_is_swappable_with_impl
2840 typedef decltype(__test<_Tp, _Up>(0)) type;
2843 // Optimization for the homogenous lvalue case, not required:
2844 template<typename _Tp>
2845 struct __is_swappable_with_impl<_Tp&, _Tp&>
2846 : public __swappable_details::__do_is_swappable_impl
2848 typedef decltype(__test<_Tp&>(0)) type;
2851 template<typename _Tp, typename _Up>
2852 struct __is_nothrow_swappable_with_impl
2853 : public __swappable_with_details::__do_is_nothrow_swappable_with_impl
2855 typedef decltype(__test<_Tp, _Up>(0)) type;
2858 // Optimization for the homogenous lvalue case, not required:
2859 template<typename _Tp>
2860 struct __is_nothrow_swappable_with_impl<_Tp&, _Tp&>
2861 : public __swappable_details::__do_is_nothrow_swappable_impl
2863 typedef decltype(__test<_Tp&>(0)) type;
2867 /// is_swappable_with
2868 template<typename _Tp, typename _Up>
2869 struct is_swappable_with
2870 : public __is_swappable_with_impl<_Tp, _Up>::type
2872 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2873 "first template argument must be a complete class or an unbounded array");
2874 static_assert(std::__is_complete_or_unbounded(__type_identity<_Up>{}),
2875 "second template argument must be a complete class or an unbounded array");
2878 /// is_nothrow_swappable_with
2879 template<typename _Tp, typename _Up>
2880 struct is_nothrow_swappable_with
2881 : public __is_nothrow_swappable_with_impl<_Tp, _Up>::type
2883 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2884 "first template argument must be a complete class or an unbounded array");
2885 static_assert(std::__is_complete_or_unbounded(__type_identity<_Up>{}),
2886 "second template argument must be a complete class or an unbounded array");
2889#if __cplusplus >= 201402L
2890 /// is_swappable_with_v
2891 template<typename _Tp, typename _Up>
2892 _GLIBCXX17_INLINE constexpr bool is_swappable_with_v =
2893 is_swappable_with<_Tp, _Up>::value;
2895 /// is_nothrow_swappable_with_v
2896 template<typename _Tp, typename _Up>
2897 _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_with_v =
2898 is_nothrow_swappable_with<_Tp, _Up>::value;
2899#endif // __cplusplus >= 201402L
2901#endif// c++1z or gnu++11
2903 /// @cond undocumented
2905 // __is_invocable (std::is_invocable for C++11)
2907 // The primary template is used for invalid INVOKE expressions.
2908 template<typename _Result, typename _Ret,
2909 bool = is_void<_Ret>::value, typename = void>
2910 struct __is_invocable_impl
2913 using __nothrow_conv = false_type; // For is_nothrow_invocable_r
2916 // Used for valid INVOKE and INVOKE<void> expressions.
2917 template<typename _Result, typename _Ret>
2918 struct __is_invocable_impl<_Result, _Ret,
2919 /* is_void<_Ret> = */ true,
2920 __void_t<typename _Result::type>>
2923 using __nothrow_conv = true_type; // For is_nothrow_invocable_r
2926#pragma GCC diagnostic push
2927#pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
2928 // Used for INVOKE<R> expressions to check the implicit conversion to R.
2929 template<typename _Result, typename _Ret>
2930 struct __is_invocable_impl<_Result, _Ret,
2931 /* is_void<_Ret> = */ false,
2932 __void_t<typename _Result::type>>
2935 // The type of the INVOKE expression.
2936 using _Res_t = typename _Result::type;
2938 // Unlike declval, this doesn't add_rvalue_reference, so it respects
2939 // guaranteed copy elision.
2940 static _Res_t _S_get() noexcept;
2942 // Used to check if _Res_t can implicitly convert to _Tp.
2943 template<typename _Tp>
2944 static void _S_conv(__type_identity_t<_Tp>) noexcept;
2946 // This overload is viable if INVOKE(f, args...) can convert to _Tp.
2947 template<typename _Tp,
2948 bool _Nothrow = noexcept(_S_conv<_Tp>(_S_get())),
2949 typename = decltype(_S_conv<_Tp>(_S_get())),
2950#if __has_builtin(__reference_converts_from_temporary)
2951 bool _Dangle = __reference_converts_from_temporary(_Tp, _Res_t)
2953 bool _Dangle = false
2956 static __bool_constant<_Nothrow && !_Dangle>
2959 template<typename _Tp, bool = false>
2964 // For is_invocable_r
2965 using type = decltype(_S_test<_Ret, /* Nothrow = */ true>(1));
2967 // For is_nothrow_invocable_r
2968 using __nothrow_conv = decltype(_S_test<_Ret>(1));
2970#pragma GCC diagnostic pop
2972 template<typename _Fn, typename... _ArgTypes>
2973 struct __is_invocable
2974 : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2977 template<typename _Fn, typename _Tp, typename... _Args>
2978 constexpr bool __call_is_nt(__invoke_memfun_ref)
2980 using _Up = typename __inv_unwrap<_Tp>::type;
2981 return noexcept((std::declval<_Up>().*std::declval<_Fn>())(
2982 std::declval<_Args>()...));
2985 template<typename _Fn, typename _Tp, typename... _Args>
2986 constexpr bool __call_is_nt(__invoke_memfun_deref)
2988 return noexcept(((*std::declval<_Tp>()).*std::declval<_Fn>())(
2989 std::declval<_Args>()...));
2992 template<typename _Fn, typename _Tp>
2993 constexpr bool __call_is_nt(__invoke_memobj_ref)
2995 using _Up = typename __inv_unwrap<_Tp>::type;
2996 return noexcept(std::declval<_Up>().*std::declval<_Fn>());
2999 template<typename _Fn, typename _Tp>
3000 constexpr bool __call_is_nt(__invoke_memobj_deref)
3002 return noexcept((*std::declval<_Tp>()).*std::declval<_Fn>());
3005 template<typename _Fn, typename... _Args>
3006 constexpr bool __call_is_nt(__invoke_other)
3008 return noexcept(std::declval<_Fn>()(std::declval<_Args>()...));
3011 template<typename _Result, typename _Fn, typename... _Args>
3012 struct __call_is_nothrow
3014 std::__call_is_nt<_Fn, _Args...>(typename _Result::__invoke_type{})
3018 template<typename _Fn, typename... _Args>
3019 using __call_is_nothrow_
3020 = __call_is_nothrow<__invoke_result<_Fn, _Args...>, _Fn, _Args...>;
3022 // __is_nothrow_invocable (std::is_nothrow_invocable for C++11)
3023 template<typename _Fn, typename... _Args>
3024 struct __is_nothrow_invocable
3025 : __and_<__is_invocable<_Fn, _Args...>,
3026 __call_is_nothrow_<_Fn, _Args...>>::type
3029#pragma GCC diagnostic push
3030#pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
3031 struct __nonesuchbase {};
3032 struct __nonesuch : private __nonesuchbase {
3033 ~__nonesuch() = delete;
3034 __nonesuch(__nonesuch const&) = delete;
3035 void operator=(__nonesuch const&) = delete;
3037#pragma GCC diagnostic pop
3040#if __cplusplus >= 201703L
3041# define __cpp_lib_is_invocable 201703L
3043 /// std::invoke_result
3044 template<typename _Functor, typename... _ArgTypes>
3045 struct invoke_result
3046 : public __invoke_result<_Functor, _ArgTypes...>
3048 static_assert(std::__is_complete_or_unbounded(__type_identity<_Functor>{}),
3049 "_Functor must be a complete class or an unbounded array");
3050 static_assert((std::__is_complete_or_unbounded(
3051 __type_identity<_ArgTypes>{}) && ...),
3052 "each argument type must be a complete class or an unbounded array");
3055 /// std::invoke_result_t
3056 template<typename _Fn, typename... _Args>
3057 using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
3059 /// std::is_invocable
3060 template<typename _Fn, typename... _ArgTypes>
3062 : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
3064 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
3065 "_Fn must be a complete class or an unbounded array");
3066 static_assert((std::__is_complete_or_unbounded(
3067 __type_identity<_ArgTypes>{}) && ...),
3068 "each argument type must be a complete class or an unbounded array");
3071 /// std::is_invocable_r
3072 template<typename _Ret, typename _Fn, typename... _ArgTypes>
3073 struct is_invocable_r
3074 : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>::type
3076 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
3077 "_Fn must be a complete class or an unbounded array");
3078 static_assert((std::__is_complete_or_unbounded(
3079 __type_identity<_ArgTypes>{}) && ...),
3080 "each argument type must be a complete class or an unbounded array");
3081 static_assert(std::__is_complete_or_unbounded(__type_identity<_Ret>{}),
3082 "_Ret must be a complete class or an unbounded array");
3085 /// std::is_nothrow_invocable
3086 template<typename _Fn, typename... _ArgTypes>
3087 struct is_nothrow_invocable
3088 : __and_<__is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>,
3089 __call_is_nothrow_<_Fn, _ArgTypes...>>::type
3091 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
3092 "_Fn must be a complete class or an unbounded array");
3093 static_assert((std::__is_complete_or_unbounded(
3094 __type_identity<_ArgTypes>{}) && ...),
3095 "each argument type must be a complete class or an unbounded array");
3098 /// @cond undocumented
3099 // This checks that the INVOKE<R> expression is well-formed and that the
3100 // conversion to R does not throw. It does *not* check whether the INVOKE
3101 // expression itself can throw. That is done by __call_is_nothrow_ instead.
3102 template<typename _Result, typename _Ret>
3103 using __is_nt_invocable_impl
3104 = typename __is_invocable_impl<_Result, _Ret>::__nothrow_conv;
3107 /// std::is_nothrow_invocable_r
3108 template<typename _Ret, typename _Fn, typename... _ArgTypes>
3109 struct is_nothrow_invocable_r
3110 : __and_<__is_nt_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>,
3111 __call_is_nothrow_<_Fn, _ArgTypes...>>::type
3113 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
3114 "_Fn must be a complete class or an unbounded array");
3115 static_assert((std::__is_complete_or_unbounded(
3116 __type_identity<_ArgTypes>{}) && ...),
3117 "each argument type must be a complete class or an unbounded array");
3118 static_assert(std::__is_complete_or_unbounded(__type_identity<_Ret>{}),
3119 "_Ret must be a complete class or an unbounded array");
3123#if __cplusplus >= 201703L
3124# define __cpp_lib_type_trait_variable_templates 201510L
3126 * @defgroup variable_templates Variable templates for type traits
3127 * @ingroup metaprogramming
3129 * Each variable `is_xxx_v<T>` is a boolean constant with the same value
3130 * as the `value` member of the corresponding type trait `is_xxx<T>`.
3132 * @since C++17 unless noted otherwise.
3137 * @ingroup variable_templates
3139template <typename _Tp>
3140 inline constexpr bool is_void_v = is_void<_Tp>::value;
3141template <typename _Tp>
3142 inline constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
3143template <typename _Tp>
3144 inline constexpr bool is_integral_v = is_integral<_Tp>::value;
3145template <typename _Tp>
3146 inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
3148template <typename _Tp>
3149 inline constexpr bool is_array_v = false;
3150template <typename _Tp>
3151 inline constexpr bool is_array_v<_Tp[]> = true;
3152template <typename _Tp, size_t _Num>
3153 inline constexpr bool is_array_v<_Tp[_Num]> = true;
3155template <typename _Tp>
3156 inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;
3157template <typename _Tp>
3158 inline constexpr bool is_lvalue_reference_v = false;
3159template <typename _Tp>
3160 inline constexpr bool is_lvalue_reference_v<_Tp&> = true;
3161template <typename _Tp>
3162 inline constexpr bool is_rvalue_reference_v = false;
3163template <typename _Tp>
3164 inline constexpr bool is_rvalue_reference_v<_Tp&&> = true;
3165template <typename _Tp>
3166 inline constexpr bool is_member_object_pointer_v =
3167 is_member_object_pointer<_Tp>::value;
3168template <typename _Tp>
3169 inline constexpr bool is_member_function_pointer_v =
3170 is_member_function_pointer<_Tp>::value;
3171template <typename _Tp>
3172 inline constexpr bool is_enum_v = __is_enum(_Tp);
3173template <typename _Tp>
3174 inline constexpr bool is_union_v = __is_union(_Tp);
3175template <typename _Tp>
3176 inline constexpr bool is_class_v = __is_class(_Tp);
3177template <typename _Tp>
3178 inline constexpr bool is_function_v = is_function<_Tp>::value;
3179template <typename _Tp>
3180 inline constexpr bool is_reference_v = false;
3181template <typename _Tp>
3182 inline constexpr bool is_reference_v<_Tp&> = true;
3183template <typename _Tp>
3184 inline constexpr bool is_reference_v<_Tp&&> = true;
3185template <typename _Tp>
3186 inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
3187template <typename _Tp>
3188 inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
3189template <typename _Tp>
3190 inline constexpr bool is_object_v = is_object<_Tp>::value;
3191template <typename _Tp>
3192 inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
3193template <typename _Tp>
3194 inline constexpr bool is_compound_v = is_compound<_Tp>::value;
3195template <typename _Tp>
3196 inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value;
3197template <typename _Tp>
3198 inline constexpr bool is_const_v = false;
3199template <typename _Tp>
3200 inline constexpr bool is_const_v<const _Tp> = true;
3201template <typename _Tp>
3202 inline constexpr bool is_volatile_v = false;
3203template <typename _Tp>
3204 inline constexpr bool is_volatile_v<volatile _Tp> = true;
3206template <typename _Tp>
3207 inline constexpr bool is_trivial_v = __is_trivial(_Tp);
3208template <typename _Tp>
3209 inline constexpr bool is_trivially_copyable_v = __is_trivially_copyable(_Tp);
3210template <typename _Tp>
3211 inline constexpr bool is_standard_layout_v = __is_standard_layout(_Tp);
3212template <typename _Tp>
3213 _GLIBCXX20_DEPRECATED("use is_standard_layout_v && is_trivial_v instead")
3214 inline constexpr bool is_pod_v = __is_pod(_Tp);
3215template <typename _Tp>
3216 _GLIBCXX17_DEPRECATED
3217 inline constexpr bool is_literal_type_v = __is_literal_type(_Tp);
3218template <typename _Tp>
3219 inline constexpr bool is_empty_v = __is_empty(_Tp);
3220template <typename _Tp>
3221 inline constexpr bool is_polymorphic_v = __is_polymorphic(_Tp);
3222template <typename _Tp>
3223 inline constexpr bool is_abstract_v = __is_abstract(_Tp);
3224template <typename _Tp>
3225 inline constexpr bool is_final_v = __is_final(_Tp);
3227template <typename _Tp>
3228 inline constexpr bool is_signed_v = is_signed<_Tp>::value;
3229template <typename _Tp>
3230 inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
3232template <typename _Tp, typename... _Args>
3233 inline constexpr bool is_constructible_v = __is_constructible(_Tp, _Args...);
3234template <typename _Tp>
3235 inline constexpr bool is_default_constructible_v = __is_constructible(_Tp);
3236template <typename _Tp>
3237 inline constexpr bool is_copy_constructible_v
3238 = __is_constructible(_Tp, __add_lval_ref_t<const _Tp>);
3239template <typename _Tp>
3240 inline constexpr bool is_move_constructible_v
3241 = __is_constructible(_Tp, __add_rval_ref_t<_Tp>);
3243template <typename _Tp, typename _Up>
3244 inline constexpr bool is_assignable_v = __is_assignable(_Tp, _Up);
3245template <typename _Tp>
3246 inline constexpr bool is_copy_assignable_v
3247 = __is_assignable(__add_lval_ref_t<_Tp>, __add_lval_ref_t<const _Tp>);
3248template <typename _Tp>
3249 inline constexpr bool is_move_assignable_v
3250 = __is_assignable(__add_lval_ref_t<_Tp>, __add_rval_ref_t<_Tp>);
3252template <typename _Tp>
3253 inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
3255template <typename _Tp, typename... _Args>
3256 inline constexpr bool is_trivially_constructible_v
3257 = __is_trivially_constructible(_Tp, _Args...);
3258template <typename _Tp>
3259 inline constexpr bool is_trivially_default_constructible_v
3260 = __is_trivially_constructible(_Tp);
3261template <typename _Tp>
3262 inline constexpr bool is_trivially_copy_constructible_v
3263 = __is_trivially_constructible(_Tp, __add_lval_ref_t<const _Tp>);
3264template <typename _Tp>
3265 inline constexpr bool is_trivially_move_constructible_v
3266 = __is_trivially_constructible(_Tp, __add_rval_ref_t<_Tp>);
3268template <typename _Tp, typename _Up>
3269 inline constexpr bool is_trivially_assignable_v
3270 = __is_trivially_assignable(_Tp, _Up);
3271template <typename _Tp>
3272 inline constexpr bool is_trivially_copy_assignable_v
3273 = __is_trivially_assignable(__add_lval_ref_t<_Tp>,
3274 __add_lval_ref_t<const _Tp>);
3275template <typename _Tp>
3276 inline constexpr bool is_trivially_move_assignable_v
3277 = __is_trivially_assignable(__add_lval_ref_t<_Tp>,
3278 __add_rval_ref_t<_Tp>);
3279template <typename _Tp>
3280 inline constexpr bool is_trivially_destructible_v =
3281 is_trivially_destructible<_Tp>::value;
3282template <typename _Tp, typename... _Args>
3283 inline constexpr bool is_nothrow_constructible_v
3284 = __is_nothrow_constructible(_Tp, _Args...);
3285template <typename _Tp>
3286 inline constexpr bool is_nothrow_default_constructible_v
3287 = __is_nothrow_constructible(_Tp);
3288template <typename _Tp>
3289 inline constexpr bool is_nothrow_copy_constructible_v
3290 = __is_nothrow_constructible(_Tp, __add_lval_ref_t<const _Tp>);
3291template <typename _Tp>
3292 inline constexpr bool is_nothrow_move_constructible_v
3293 = __is_nothrow_constructible(_Tp, __add_rval_ref_t<_Tp>);
3295template <typename _Tp, typename _Up>
3296 inline constexpr bool is_nothrow_assignable_v
3297 = __is_nothrow_assignable(_Tp, _Up);
3298template <typename _Tp>
3299 inline constexpr bool is_nothrow_copy_assignable_v
3300 = __is_nothrow_assignable(__add_lval_ref_t<_Tp>,
3301 __add_lval_ref_t<const _Tp>);
3302template <typename _Tp>
3303 inline constexpr bool is_nothrow_move_assignable_v
3304 = __is_nothrow_assignable(__add_lval_ref_t<_Tp>, __add_rval_ref_t<_Tp>);
3306template <typename _Tp>
3307 inline constexpr bool is_nothrow_destructible_v =
3308 is_nothrow_destructible<_Tp>::value;
3310template <typename _Tp>
3311 inline constexpr bool has_virtual_destructor_v
3312 = __has_virtual_destructor(_Tp);
3314template <typename _Tp>
3315 inline constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
3317template <typename _Tp>
3318 inline constexpr size_t rank_v = 0;
3319template <typename _Tp, size_t _Size>
3320 inline constexpr size_t rank_v<_Tp[_Size]> = 1 + rank_v<_Tp>;
3321template <typename _Tp>
3322 inline constexpr size_t rank_v<_Tp[]> = 1 + rank_v<_Tp>;
3324template <typename _Tp, unsigned _Idx = 0>
3325 inline constexpr size_t extent_v = 0;
3326template <typename _Tp, size_t _Size>
3327 inline constexpr size_t extent_v<_Tp[_Size], 0> = _Size;
3328template <typename _Tp, unsigned _Idx, size_t _Size>
3329 inline constexpr size_t extent_v<_Tp[_Size], _Idx> = extent_v<_Tp, _Idx - 1>;
3330template <typename _Tp>
3331 inline constexpr size_t extent_v<_Tp[], 0> = 0;
3332template <typename _Tp, unsigned _Idx>
3333 inline constexpr size_t extent_v<_Tp[], _Idx> = extent_v<_Tp, _Idx - 1>;
3335#ifdef _GLIBCXX_HAVE_BUILTIN_IS_SAME
3336template <typename _Tp, typename _Up>
3337 inline constexpr bool is_same_v = __is_same(_Tp, _Up);
3339template <typename _Tp, typename _Up>
3340 inline constexpr bool is_same_v = false;
3341template <typename _Tp>
3342 inline constexpr bool is_same_v<_Tp, _Tp> = true;
3344template <typename _Base, typename _Derived>
3345 inline constexpr bool is_base_of_v = __is_base_of(_Base, _Derived);
3346template <typename _From, typename _To>
3347 inline constexpr bool is_convertible_v = __is_convertible(_From, _To);
3348template<typename _Fn, typename... _Args>
3349 inline constexpr bool is_invocable_v = is_invocable<_Fn, _Args...>::value;
3350template<typename _Fn, typename... _Args>
3351 inline constexpr bool is_nothrow_invocable_v
3352 = is_nothrow_invocable<_Fn, _Args...>::value;
3353template<typename _Ret, typename _Fn, typename... _Args>
3354 inline constexpr bool is_invocable_r_v
3355 = is_invocable_r<_Ret, _Fn, _Args...>::value;
3356template<typename _Ret, typename _Fn, typename... _Args>
3357 inline constexpr bool is_nothrow_invocable_r_v
3358 = is_nothrow_invocable_r<_Ret, _Fn, _Args...>::value;
3361#ifdef _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP
3362# define __cpp_lib_has_unique_object_representations 201606L
3363 /// has_unique_object_representations
3365 template<typename _Tp>
3366 struct has_unique_object_representations
3367 : bool_constant<__has_unique_object_representations(
3368 remove_cv_t<remove_all_extents_t<_Tp>>
3371 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
3372 "template argument must be a complete class or an unbounded array");
3375 /// @ingroup variable_templates
3376 template<typename _Tp>
3377 inline constexpr bool has_unique_object_representations_v
3378 = has_unique_object_representations<_Tp>::value;
3381#ifdef _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE
3382# define __cpp_lib_is_aggregate 201703L
3383 /// is_aggregate - true if the type is an aggregate.
3385 template<typename _Tp>
3387 : bool_constant<__is_aggregate(remove_cv_t<_Tp>)>
3390 /** is_aggregate_v - true if the type is an aggregate.
3391 * @ingroup variable_templates
3394 template<typename _Tp>
3395 inline constexpr bool is_aggregate_v = __is_aggregate(remove_cv_t<_Tp>);
3399#if __cplusplus >= 202002L
3401 /** * Remove references and cv-qualifiers.
3405#define __cpp_lib_remove_cvref 201711L
3407#if __has_builtin(__remove_cvref)
3408 template<typename _Tp>
3410 { using type = __remove_cvref(_Tp); };
3412 template<typename _Tp>
3414 { using type = typename remove_cv<_Tp>::type; };
3416 template<typename _Tp>
3417 struct remove_cvref<_Tp&>
3418 { using type = typename remove_cv<_Tp>::type; };
3420 template<typename _Tp>
3421 struct remove_cvref<_Tp&&>
3422 { using type = typename remove_cv<_Tp>::type; };
3425 template<typename _Tp>
3426 using remove_cvref_t = typename remove_cvref<_Tp>::type;
3429 /** * Identity metafunction.
3433#define __cpp_lib_type_identity 201806L
3434 template<typename _Tp>
3435 struct type_identity { using type = _Tp; };
3437 template<typename _Tp>
3438 using type_identity_t = typename type_identity<_Tp>::type;
3441#define __cpp_lib_unwrap_ref 201811L
3443 /** Unwrap a reference_wrapper
3447 template<typename _Tp>
3448 struct unwrap_reference { using type = _Tp; };
3450 template<typename _Tp>
3451 struct unwrap_reference<reference_wrapper<_Tp>> { using type = _Tp&; };
3453 template<typename _Tp>
3454 using unwrap_reference_t = typename unwrap_reference<_Tp>::type;
3457 /** Decay type and if it's a reference_wrapper, unwrap it
3461 template<typename _Tp>
3462 struct unwrap_ref_decay { using type = unwrap_reference_t<decay_t<_Tp>>; };
3464 template<typename _Tp>
3465 using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
3468#define __cpp_lib_bounded_array_traits 201902L
3470 /// True for a type that is an array of known bound.
3471 /// @ingroup variable_templates
3473 template<typename _Tp>
3474 inline constexpr bool is_bounded_array_v = false;
3476 template<typename _Tp, size_t _Size>
3477 inline constexpr bool is_bounded_array_v<_Tp[_Size]> = true;
3479 /// True for a type that is an array of unknown bound.
3480 /// @ingroup variable_templates
3482 template<typename _Tp>
3483 inline constexpr bool is_unbounded_array_v = false;
3485 template<typename _Tp>
3486 inline constexpr bool is_unbounded_array_v<_Tp[]> = true;
3488 /// True for a type that is an array of known bound.
3490 template<typename _Tp>
3491 struct is_bounded_array
3492 : public bool_constant<is_bounded_array_v<_Tp>>
3495 /// True for a type that is an array of unknown bound.
3497 template<typename _Tp>
3498 struct is_unbounded_array
3499 : public bool_constant<is_unbounded_array_v<_Tp>>
3502#if __has_builtin(__is_layout_compatible)
3505 template<typename _Tp, typename _Up>
3506 struct is_layout_compatible
3507 : bool_constant<__is_layout_compatible(_Tp, _Up)>
3510 /// @ingroup variable_templates
3512 template<typename _Tp, typename _Up>
3513 constexpr bool is_layout_compatible_v
3514 = __is_layout_compatible(_Tp, _Up);
3516#if __has_builtin(__builtin_is_corresponding_member)
3517#define __cpp_lib_is_layout_compatible 201907L
3520 template<typename _S1, typename _S2, typename _M1, typename _M2>
3522 is_corresponding_member(_M1 _S1::*__m1, _M2 _S2::*__m2) noexcept
3523 { return __builtin_is_corresponding_member(__m1, __m2); }
3527#if __has_builtin(__is_pointer_interconvertible_base_of)
3528 /// True if `_Derived` is standard-layout and has a base class of type `_Base`
3530 template<typename _Base, typename _Derived>
3531 struct is_pointer_interconvertible_base_of
3532 : bool_constant<__is_pointer_interconvertible_base_of(_Base, _Derived)>
3535 /// @ingroup variable_templates
3537 template<typename _Base, typename _Derived>
3538 constexpr bool is_pointer_interconvertible_base_of_v
3539 = __is_pointer_interconvertible_base_of(_Base, _Derived);
3541#if __has_builtin(__builtin_is_pointer_interconvertible_with_class)
3542#define __cpp_lib_is_pointer_interconvertible 201907L
3544 /// True if `__mp` points to the first member of a standard-layout type
3545 /// @returns true if `s.*__mp` is pointer-interconvertible with `s`
3547 template<typename _Tp, typename _Mem>
3549 is_pointer_interconvertible_with_class(_Mem _Tp::*__mp) noexcept
3550 { return __builtin_is_pointer_interconvertible_with_class(__mp); }
3554#if __cplusplus > 202002L
3555#define __cpp_lib_is_scoped_enum 202011L
3557 /// True if the type is a scoped enumeration type.
3560 template<typename _Tp>
3561 struct is_scoped_enum
3565 template<typename _Tp>
3566 requires __is_enum(_Tp)
3567 && requires(remove_cv_t<_Tp> __t) { __t = __t; } // fails if incomplete
3568 struct is_scoped_enum<_Tp>
3569 : bool_constant<!requires(_Tp __t, void(*__f)(int)) { __f(__t); }>
3572 /// @ingroup variable_templates
3574 template<typename _Tp>
3575 inline constexpr bool is_scoped_enum_v = is_scoped_enum<_Tp>::value;
3577#if __has_builtin(__reference_constructs_from_temporary) \
3578 && __has_builtin(__reference_converts_from_temporary)
3580#define __cpp_lib_reference_from_temporary 202202L
3582 /// True if _Tp is a reference type, a _Up value can be bound to _Tp in
3583 /// direct-initialization, and a temporary object would be bound to
3584 /// the reference, false otherwise.
3586 template<typename _Tp, typename _Up>
3587 struct reference_constructs_from_temporary
3588 : public bool_constant<__reference_constructs_from_temporary(_Tp, _Up)>
3590 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{})
3591 && std::__is_complete_or_unbounded(__type_identity<_Up>{}),
3592 "template argument must be a complete class or an unbounded array");
3595 /// True if _Tp is a reference type, a _Up value can be bound to _Tp in
3596 /// copy-initialization, and a temporary object would be bound to
3597 /// the reference, false otherwise.
3599 template<typename _Tp, typename _Up>
3600 struct reference_converts_from_temporary
3601 : public bool_constant<__reference_converts_from_temporary(_Tp, _Up)>
3603 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{})
3604 && std::__is_complete_or_unbounded(__type_identity<_Up>{}),
3605 "template argument must be a complete class or an unbounded array");
3608 /// @ingroup variable_templates
3610 template<typename _Tp, typename _Up>
3611 inline constexpr bool reference_constructs_from_temporary_v
3612 = reference_constructs_from_temporary<_Tp, _Up>::value;
3614 /// @ingroup variable_templates
3616 template<typename _Tp, typename _Up>
3617 inline constexpr bool reference_converts_from_temporary_v
3618 = reference_converts_from_temporary<_Tp, _Up>::value;
3619#endif // __has_builtin for reference_from_temporary
3622#if _GLIBCXX_HAVE_IS_CONSTANT_EVALUATED
3623#define __cpp_lib_is_constant_evaluated 201811L
3625 /// Returns true only when called during constant evaluation.
3627 constexpr inline bool
3628 is_constant_evaluated() noexcept
3630#if __cpp_if_consteval >= 202106L
3631 if consteval { return true; } else { return false; }
3633 return __builtin_is_constant_evaluated();
3638 /// @cond undocumented
3639 template<typename _From, typename _To>
3640 using __copy_cv = typename __match_cv_qualifiers<_From, _To>::__type;
3642 template<typename _Xp, typename _Yp>
3644 = decltype(false ? declval<_Xp(&)()>()() : declval<_Yp(&)()>()());
3646 template<typename _Ap, typename _Bp, typename = void>
3647 struct __common_ref_impl
3650 // [meta.trans.other], COMMON-REF(A, B)
3651 template<typename _Ap, typename _Bp>
3652 using __common_ref = typename __common_ref_impl<_Ap, _Bp>::type;
3654 // COND-RES(COPYCV(X, Y) &, COPYCV(Y, X) &)
3655 template<typename _Xp, typename _Yp>
3656 using __condres_cvref
3657 = __cond_res<__copy_cv<_Xp, _Yp>&, __copy_cv<_Yp, _Xp>&>;
3659 // If A and B are both lvalue reference types, ...
3660 template<typename _Xp, typename _Yp>
3661 struct __common_ref_impl<_Xp&, _Yp&, __void_t<__condres_cvref<_Xp, _Yp>>>
3662 : enable_if<is_reference_v<__condres_cvref<_Xp, _Yp>>,
3663 __condres_cvref<_Xp, _Yp>>
3666 // let C be remove_reference_t<COMMON-REF(X&, Y&)>&&
3667 template<typename _Xp, typename _Yp>
3668 using __common_ref_C = remove_reference_t<__common_ref<_Xp&, _Yp&>>&&;
3670 // If A and B are both rvalue reference types, ...
3671 template<typename _Xp, typename _Yp>
3672 struct __common_ref_impl<_Xp&&, _Yp&&,
3673 _Require<is_convertible<_Xp&&, __common_ref_C<_Xp, _Yp>>,
3674 is_convertible<_Yp&&, __common_ref_C<_Xp, _Yp>>>>
3675 { using type = __common_ref_C<_Xp, _Yp>; };
3677 // let D be COMMON-REF(const X&, Y&)
3678 template<typename _Xp, typename _Yp>
3679 using __common_ref_D = __common_ref<const _Xp&, _Yp&>;
3681 // If A is an rvalue reference and B is an lvalue reference, ...
3682 template<typename _Xp, typename _Yp>
3683 struct __common_ref_impl<_Xp&&, _Yp&,
3684 _Require<is_convertible<_Xp&&, __common_ref_D<_Xp, _Yp>>>>
3685 { using type = __common_ref_D<_Xp, _Yp>; };
3687 // If A is an lvalue reference and B is an rvalue reference, ...
3688 template<typename _Xp, typename _Yp>
3689 struct __common_ref_impl<_Xp&, _Yp&&>
3690 : __common_ref_impl<_Yp&&, _Xp&>
3694 template<typename _Tp, typename _Up,
3695 template<typename> class _TQual, template<typename> class _UQual>
3696 struct basic_common_reference
3699 /// @cond undocumented
3700 template<typename _Tp>
3702 { template<typename _Up> using __type = __copy_cv<_Tp, _Up>; };
3704 template<typename _Tp>
3706 { template<typename _Up> using __type = __copy_cv<_Tp, _Up>&; };
3708 template<typename _Tp>
3709 struct __xref<_Tp&&>
3710 { template<typename _Up> using __type = __copy_cv<_Tp, _Up>&&; };
3712 template<typename _Tp1, typename _Tp2>
3713 using __basic_common_ref
3714 = typename basic_common_reference<remove_cvref_t<_Tp1>,
3715 remove_cvref_t<_Tp2>,
3716 __xref<_Tp1>::template __type,
3717 __xref<_Tp2>::template __type>::type;
3720 template<typename... _Tp>
3721 struct common_reference;
3723 template<typename... _Tp>
3724 using common_reference_t = typename common_reference<_Tp...>::type;
3726 // If sizeof...(T) is zero, there shall be no member type.
3728 struct common_reference<>
3731 // If sizeof...(T) is one ...
3732 template<typename _Tp0>
3733 struct common_reference<_Tp0>
3734 { using type = _Tp0; };
3736 /// @cond undocumented
3737 template<typename _Tp1, typename _Tp2, int _Bullet = 1, typename = void>
3738 struct __common_reference_impl
3739 : __common_reference_impl<_Tp1, _Tp2, _Bullet + 1>
3742 // If sizeof...(T) is two ...
3743 template<typename _Tp1, typename _Tp2>
3744 struct common_reference<_Tp1, _Tp2>
3745 : __common_reference_impl<_Tp1, _Tp2>
3748 // If T1 and T2 are reference types and COMMON-REF(T1, T2) is well-formed, ...
3749 template<typename _Tp1, typename _Tp2>
3750 struct __common_reference_impl<_Tp1&, _Tp2&, 1,
3751 void_t<__common_ref<_Tp1&, _Tp2&>>>
3752 { using type = __common_ref<_Tp1&, _Tp2&>; };
3754 template<typename _Tp1, typename _Tp2>
3755 struct __common_reference_impl<_Tp1&&, _Tp2&&, 1,
3756 void_t<__common_ref<_Tp1&&, _Tp2&&>>>
3757 { using type = __common_ref<_Tp1&&, _Tp2&&>; };
3759 template<typename _Tp1, typename _Tp2>
3760 struct __common_reference_impl<_Tp1&, _Tp2&&, 1,
3761 void_t<__common_ref<_Tp1&, _Tp2&&>>>
3762 { using type = __common_ref<_Tp1&, _Tp2&&>; };
3764 template<typename _Tp1, typename _Tp2>
3765 struct __common_reference_impl<_Tp1&&, _Tp2&, 1,
3766 void_t<__common_ref<_Tp1&&, _Tp2&>>>
3767 { using type = __common_ref<_Tp1&&, _Tp2&>; };
3769 // Otherwise, if basic_common_reference<...>::type is well-formed, ...
3770 template<typename _Tp1, typename _Tp2>
3771 struct __common_reference_impl<_Tp1, _Tp2, 2,
3772 void_t<__basic_common_ref<_Tp1, _Tp2>>>
3773 { using type = __basic_common_ref<_Tp1, _Tp2>; };
3775 // Otherwise, if COND-RES(T1, T2) is well-formed, ...
3776 template<typename _Tp1, typename _Tp2>
3777 struct __common_reference_impl<_Tp1, _Tp2, 3,
3778 void_t<__cond_res<_Tp1, _Tp2>>>
3779 { using type = __cond_res<_Tp1, _Tp2>; };
3781 // Otherwise, if common_type_t<T1, T2> is well-formed, ...
3782 template<typename _Tp1, typename _Tp2>
3783 struct __common_reference_impl<_Tp1, _Tp2, 4,
3784 void_t<common_type_t<_Tp1, _Tp2>>>
3785 { using type = common_type_t<_Tp1, _Tp2>; };
3787 // Otherwise, there shall be no member type.
3788 template<typename _Tp1, typename _Tp2>
3789 struct __common_reference_impl<_Tp1, _Tp2, 5, void>
3792 // Otherwise, if sizeof...(T) is greater than two, ...
3793 template<typename _Tp1, typename _Tp2, typename... _Rest>
3794 struct common_reference<_Tp1, _Tp2, _Rest...>
3795 : __common_type_fold<common_reference<_Tp1, _Tp2>,
3796 __common_type_pack<_Rest...>>
3799 // Reuse __common_type_fold for common_reference<T1, T2, Rest...>
3800 template<typename _Tp1, typename _Tp2, typename... _Rest>
3801 struct __common_type_fold<common_reference<_Tp1, _Tp2>,
3802 __common_type_pack<_Rest...>,
3803 void_t<common_reference_t<_Tp1, _Tp2>>>
3804 : public common_reference<common_reference_t<_Tp1, _Tp2>, _Rest...>
3810 /// @} group metaprogramming
3812_GLIBCXX_END_NAMESPACE_VERSION
3817#endif // _GLIBCXX_TYPE_TRAITS