1 // C++11 <type_traits> -*- C++ -*-
3 // Copyright (C) 2007-2020 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file include/type_traits
26 * This is a Standard C++ Library header.
29 #ifndef _GLIBCXX_TYPE_TRAITS
30 #define _GLIBCXX_TYPE_TRAITS 1
32 #pragma GCC system_header
34 #if __cplusplus < 201103L
35 # include <bits/c++0x_warning.h>
38 #include <bits/c++config.h>
40 namespace std _GLIBCXX_VISIBILITY(default)
42 _GLIBCXX_BEGIN_NAMESPACE_VERSION
45 * @defgroup metaprogramming Metaprogramming
48 * Template utilities for compile-time introspection and modification,
49 * including type classification traits, type property inspection traits
50 * and type transformation traits.
56 template<typename _Tp, _Tp __v>
57 struct integral_constant
59 static constexpr _Tp value = __v;
60 typedef _Tp value_type;
61 typedef integral_constant<_Tp, __v> type;
62 constexpr operator value_type() const noexcept { return value; }
63 #if __cplusplus > 201103L
65 #define __cpp_lib_integral_constant_callable 201304
67 constexpr value_type operator()() const noexcept { return value; }
71 template<typename _Tp, _Tp __v>
72 constexpr _Tp integral_constant<_Tp, __v>::value;
74 /// The type used as a compile-time boolean with true value.
75 typedef integral_constant<bool, true> true_type;
77 /// The type used as a compile-time boolean with false value.
78 typedef integral_constant<bool, false> false_type;
81 using __bool_constant = integral_constant<bool, __v>;
83 #if __cplusplus > 201402L
84 # define __cpp_lib_bool_constant 201505
86 using bool_constant = integral_constant<bool, __v>;
89 // Meta programming helper types.
91 template<bool, typename, typename>
94 template <typename _Type>
95 struct __type_identity
96 { using type = _Type; };
98 template<typename _Tp>
99 using __type_identity_t = typename __type_identity<_Tp>::type;
101 template<typename...>
109 template<typename _B1>
114 template<typename _B1, typename _B2>
115 struct __or_<_B1, _B2>
116 : public conditional<_B1::value, _B1, _B2>::type
119 template<typename _B1, typename _B2, typename _B3, typename... _Bn>
120 struct __or_<_B1, _B2, _B3, _Bn...>
121 : public conditional<_B1::value, _B1, __or_<_B2, _B3, _Bn...>>::type
124 template<typename...>
132 template<typename _B1>
137 template<typename _B1, typename _B2>
138 struct __and_<_B1, _B2>
139 : public conditional<_B1::value, _B2, _B1>::type
142 template<typename _B1, typename _B2, typename _B3, typename... _Bn>
143 struct __and_<_B1, _B2, _B3, _Bn...>
144 : public conditional<_B1::value, __and_<_B2, _B3, _Bn...>, _B1>::type
147 template<typename _Pp>
149 : public __bool_constant<!bool(_Pp::value)>
152 #if __cplusplus >= 201703L
154 template<typename... _Bn>
155 inline constexpr bool __or_v = __or_<_Bn...>::value;
156 template<typename... _Bn>
157 inline constexpr bool __and_v = __and_<_Bn...>::value;
159 #define __cpp_lib_logical_traits 201510
161 template<typename... _Bn>
166 template<typename... _Bn>
171 template<typename _Pp>
176 template<typename... _Bn>
177 inline constexpr bool conjunction_v = conjunction<_Bn...>::value;
179 template<typename... _Bn>
180 inline constexpr bool disjunction_v = disjunction<_Bn...>::value;
182 template<typename _Pp>
183 inline constexpr bool negation_v = negation<_Pp>::value;
187 // Forward declarations
195 struct __is_array_unknown_bounds;
197 // Helper functions that return false_type for incomplete classes,
198 // incomplete unions and arrays of known bound from those.
200 template <typename _T, size_t = sizeof(_T)>
201 constexpr true_type __is_complete_or_unbounded(__type_identity<_T>)
204 template <typename _TypeIdentity,
205 typename _NestedType = typename _TypeIdentity::type>
206 constexpr typename __or_<
207 is_reference<_NestedType>,
208 is_function<_NestedType>,
209 is_void<_NestedType>,
210 __is_array_unknown_bounds<_NestedType>
211 >::type __is_complete_or_unbounded(_TypeIdentity)
214 // For several sfinae-friendly trait implementations we transport both the
215 // result information (as the member type) and the failure information (no
216 // member type). This is very similar to std::enable_if, but we cannot use
217 // them, because we need to derive from them as an implementation detail.
219 template<typename _Tp>
220 struct __success_type
221 { typedef _Tp type; };
223 struct __failure_type
229 // __remove_cv_t (std::remove_cv_t for C++11).
230 template<typename _Tp>
231 using __remove_cv_t = typename remove_cv<_Tp>::type;
236 // Primary type categories.
239 struct __is_void_helper
240 : public false_type { };
243 struct __is_void_helper<void>
244 : public true_type { };
247 template<typename _Tp>
249 : public __is_void_helper<__remove_cv_t<_Tp>>::type
253 struct __is_integral_helper
254 : public false_type { };
257 struct __is_integral_helper<bool>
258 : public true_type { };
261 struct __is_integral_helper<char>
262 : public true_type { };
265 struct __is_integral_helper<signed char>
266 : public true_type { };
269 struct __is_integral_helper<unsigned char>
270 : public true_type { };
272 #ifdef _GLIBCXX_USE_WCHAR_T
274 struct __is_integral_helper<wchar_t>
275 : public true_type { };
278 #ifdef _GLIBCXX_USE_CHAR8_T
280 struct __is_integral_helper<char8_t>
281 : public true_type { };
285 struct __is_integral_helper<char16_t>
286 : public true_type { };
289 struct __is_integral_helper<char32_t>
290 : public true_type { };
293 struct __is_integral_helper<short>
294 : public true_type { };
297 struct __is_integral_helper<unsigned short>
298 : public true_type { };
301 struct __is_integral_helper<int>
302 : public true_type { };
305 struct __is_integral_helper<unsigned int>
306 : public true_type { };
309 struct __is_integral_helper<long>
310 : public true_type { };
313 struct __is_integral_helper<unsigned long>
314 : public true_type { };
317 struct __is_integral_helper<long long>
318 : public true_type { };
321 struct __is_integral_helper<unsigned long long>
322 : public true_type { };
324 // Conditionalizing on __STRICT_ANSI__ here will break any port that
325 // uses one of these types for size_t.
326 #if defined(__GLIBCXX_TYPE_INT_N_0)
328 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_0>
329 : public true_type { };
332 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_0>
333 : public true_type { };
335 #if defined(__GLIBCXX_TYPE_INT_N_1)
337 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_1>
338 : public true_type { };
341 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_1>
342 : public true_type { };
344 #if defined(__GLIBCXX_TYPE_INT_N_2)
346 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_2>
347 : public true_type { };
350 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_2>
351 : public true_type { };
353 #if defined(__GLIBCXX_TYPE_INT_N_3)
355 struct __is_integral_helper<__GLIBCXX_TYPE_INT_N_3>
356 : public true_type { };
359 struct __is_integral_helper<unsigned __GLIBCXX_TYPE_INT_N_3>
360 : public true_type { };
364 template<typename _Tp>
366 : public __is_integral_helper<__remove_cv_t<_Tp>>::type
370 struct __is_floating_point_helper
371 : public false_type { };
374 struct __is_floating_point_helper<float>
375 : public true_type { };
378 struct __is_floating_point_helper<double>
379 : public true_type { };
382 struct __is_floating_point_helper<long double>
383 : public true_type { };
385 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
387 struct __is_floating_point_helper<__float128>
388 : public true_type { };
391 /// is_floating_point
392 template<typename _Tp>
393 struct is_floating_point
394 : public __is_floating_point_helper<__remove_cv_t<_Tp>>::type
400 : public false_type { };
402 template<typename _Tp, std::size_t _Size>
403 struct is_array<_Tp[_Size]>
404 : public true_type { };
406 template<typename _Tp>
407 struct is_array<_Tp[]>
408 : public true_type { };
411 struct __is_pointer_helper
412 : public false_type { };
414 template<typename _Tp>
415 struct __is_pointer_helper<_Tp*>
416 : public true_type { };
419 template<typename _Tp>
421 : public __is_pointer_helper<__remove_cv_t<_Tp>>::type
424 /// is_lvalue_reference
426 struct is_lvalue_reference
427 : public false_type { };
429 template<typename _Tp>
430 struct is_lvalue_reference<_Tp&>
431 : public true_type { };
433 /// is_rvalue_reference
435 struct is_rvalue_reference
436 : public false_type { };
438 template<typename _Tp>
439 struct is_rvalue_reference<_Tp&&>
440 : public true_type { };
443 struct __is_member_object_pointer_helper
444 : public false_type { };
446 template<typename _Tp, typename _Cp>
447 struct __is_member_object_pointer_helper<_Tp _Cp::*>
448 : public __not_<is_function<_Tp>>::type { };
450 /// is_member_object_pointer
451 template<typename _Tp>
452 struct is_member_object_pointer
453 : public __is_member_object_pointer_helper<__remove_cv_t<_Tp>>::type
457 struct __is_member_function_pointer_helper
458 : public false_type { };
460 template<typename _Tp, typename _Cp>
461 struct __is_member_function_pointer_helper<_Tp _Cp::*>
462 : public is_function<_Tp>::type { };
464 /// is_member_function_pointer
465 template<typename _Tp>
466 struct is_member_function_pointer
467 : public __is_member_function_pointer_helper<__remove_cv_t<_Tp>>::type
471 template<typename _Tp>
473 : public integral_constant<bool, __is_enum(_Tp)>
477 template<typename _Tp>
479 : public integral_constant<bool, __is_union(_Tp)>
483 template<typename _Tp>
485 : public integral_constant<bool, __is_class(_Tp)>
489 template<typename _Tp>
491 : public __bool_constant<!is_const<const _Tp>::value> { };
493 template<typename _Tp>
494 struct is_function<_Tp&>
495 : public false_type { };
497 template<typename _Tp>
498 struct is_function<_Tp&&>
499 : public false_type { };
501 #define __cpp_lib_is_null_pointer 201309
504 struct __is_null_pointer_helper
505 : public false_type { };
508 struct __is_null_pointer_helper<std::nullptr_t>
509 : public true_type { };
511 /// is_null_pointer (LWG 2247).
512 template<typename _Tp>
513 struct is_null_pointer
514 : public __is_null_pointer_helper<__remove_cv_t<_Tp>>::type
517 /// __is_nullptr_t (deprecated extension).
518 template<typename _Tp>
519 struct __is_nullptr_t
520 : public is_null_pointer<_Tp>
521 { } _GLIBCXX_DEPRECATED;
523 // Composite type categories.
526 template<typename _Tp>
528 : public __or_<is_lvalue_reference<_Tp>,
529 is_rvalue_reference<_Tp>>::type
533 template<typename _Tp>
535 : public __or_<is_integral<_Tp>, is_floating_point<_Tp>>::type
539 template<typename _Tp>
540 struct is_fundamental
541 : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
542 is_null_pointer<_Tp>>::type
546 template<typename _Tp>
548 : public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
553 struct is_member_pointer;
556 template<typename _Tp>
558 : public __or_<is_arithmetic<_Tp>, is_enum<_Tp>, is_pointer<_Tp>,
559 is_member_pointer<_Tp>, is_null_pointer<_Tp>>::type
563 template<typename _Tp>
565 : public __not_<is_fundamental<_Tp>>::type { };
567 template<typename _Tp>
568 struct __is_member_pointer_helper
569 : public false_type { };
571 template<typename _Tp, typename _Cp>
572 struct __is_member_pointer_helper<_Tp _Cp::*>
573 : public true_type { };
575 /// is_member_pointer
576 template<typename _Tp>
577 struct is_member_pointer
578 : public __is_member_pointer_helper<__remove_cv_t<_Tp>>::type
581 template<typename, typename>
584 template<typename _Tp, typename... _Types>
585 using __is_one_of = __or_<is_same<_Tp, _Types>...>;
587 // Check if a type is one of the signed integer types.
588 template<typename _Tp>
589 using __is_signed_integer = __is_one_of<__remove_cv_t<_Tp>,
590 signed char, signed short, signed int, signed long,
592 #if defined(__GLIBCXX_TYPE_INT_N_0)
593 , signed __GLIBCXX_TYPE_INT_N_0
595 #if defined(__GLIBCXX_TYPE_INT_N_1)
596 , signed __GLIBCXX_TYPE_INT_N_1
598 #if defined(__GLIBCXX_TYPE_INT_N_2)
599 , signed __GLIBCXX_TYPE_INT_N_2
601 #if defined(__GLIBCXX_TYPE_INT_N_3)
602 , signed __GLIBCXX_TYPE_INT_N_3
606 // Check if a type is one of the unsigned integer types.
607 template<typename _Tp>
608 using __is_unsigned_integer = __is_one_of<__remove_cv_t<_Tp>,
609 unsigned char, unsigned short, unsigned int, unsigned long,
611 #if defined(__GLIBCXX_TYPE_INT_N_0)
612 , unsigned __GLIBCXX_TYPE_INT_N_0
614 #if defined(__GLIBCXX_TYPE_INT_N_1)
615 , unsigned __GLIBCXX_TYPE_INT_N_1
617 #if defined(__GLIBCXX_TYPE_INT_N_2)
618 , unsigned __GLIBCXX_TYPE_INT_N_2
620 #if defined(__GLIBCXX_TYPE_INT_N_3)
621 , unsigned __GLIBCXX_TYPE_INT_N_3
625 // Check if a type is one of the signed or unsigned integer types.
626 template<typename _Tp>
627 using __is_standard_integer
628 = __or_<__is_signed_integer<_Tp>, __is_unsigned_integer<_Tp>>;
630 // __void_t (std::void_t for C++11)
631 template<typename...> using __void_t = void;
633 // Utility to detect referenceable types ([defns.referenceable]).
635 template<typename _Tp, typename = void>
636 struct __is_referenceable
640 template<typename _Tp>
641 struct __is_referenceable<_Tp, __void_t<_Tp&>>
650 : public false_type { };
652 template<typename _Tp>
653 struct is_const<_Tp const>
654 : public true_type { };
659 : public false_type { };
661 template<typename _Tp>
662 struct is_volatile<_Tp volatile>
663 : public true_type { };
666 template<typename _Tp>
668 : public integral_constant<bool, __is_trivial(_Tp)>
670 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
671 "template argument must be a complete class or an unbounded array");
674 // is_trivially_copyable
675 template<typename _Tp>
676 struct is_trivially_copyable
677 : public integral_constant<bool, __is_trivially_copyable(_Tp)>
679 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
680 "template argument must be a complete class or an unbounded array");
683 /// is_standard_layout
684 template<typename _Tp>
685 struct is_standard_layout
686 : public integral_constant<bool, __is_standard_layout(_Tp)>
688 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
689 "template argument must be a complete class or an unbounded array");
692 /// is_pod (deprecated in C++20)
693 // Could use is_standard_layout && is_trivial instead of the builtin.
694 template<typename _Tp>
696 _GLIBCXX20_DEPRECATED("use is_standard_layout && is_trivial instead")
698 : public integral_constant<bool, __is_pod(_Tp)>
700 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
701 "template argument must be a complete class or an unbounded array");
705 template<typename _Tp>
706 struct is_literal_type
707 : public integral_constant<bool, __is_literal_type(_Tp)>
709 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
710 "template argument must be a complete class or an unbounded array");
714 template<typename _Tp>
716 : public integral_constant<bool, __is_empty(_Tp)>
720 template<typename _Tp>
721 struct is_polymorphic
722 : public integral_constant<bool, __is_polymorphic(_Tp)>
725 #if __cplusplus >= 201402L
726 #define __cpp_lib_is_final 201402L
728 template<typename _Tp>
730 : public integral_constant<bool, __is_final(_Tp)>
735 template<typename _Tp>
737 : public integral_constant<bool, __is_abstract(_Tp)>
740 template<typename _Tp,
741 bool = is_arithmetic<_Tp>::value>
742 struct __is_signed_helper
743 : public false_type { };
745 template<typename _Tp>
746 struct __is_signed_helper<_Tp, true>
747 : public integral_constant<bool, _Tp(-1) < _Tp(0)>
751 template<typename _Tp>
753 : public __is_signed_helper<_Tp>::type
757 template<typename _Tp>
759 : public __and_<is_arithmetic<_Tp>, __not_<is_signed<_Tp>>>
763 // Destructible and constructible type properties.
766 * @brief Utility to simplify expressions used in unevaluated operands
770 template<typename _Tp, typename _Up = _Tp&&>
774 template<typename _Tp>
778 template<typename _Tp>
779 auto declval() noexcept -> decltype(__declval<_Tp>(0));
781 template<typename, unsigned = 0>
785 struct remove_all_extents;
787 template<typename _Tp>
788 struct __is_array_known_bounds
789 : public integral_constant<bool, (extent<_Tp>::value > 0)>
792 template<typename _Tp>
793 struct __is_array_unknown_bounds
794 : public __and_<is_array<_Tp>, __not_<extent<_Tp>>>
797 // In N3290 is_destructible does not say anything about function
798 // types and abstract types, see LWG 2049. This implementation
799 // describes function types as non-destructible and all complete
800 // object types as destructible, iff the explicit destructor
801 // call expression is wellformed.
802 struct __do_is_destructible_impl
804 template<typename _Tp, typename = decltype(declval<_Tp&>().~_Tp())>
805 static true_type __test(int);
808 static false_type __test(...);
811 template<typename _Tp>
812 struct __is_destructible_impl
813 : public __do_is_destructible_impl
815 typedef decltype(__test<_Tp>(0)) type;
818 template<typename _Tp,
819 bool = __or_<is_void<_Tp>,
820 __is_array_unknown_bounds<_Tp>,
821 is_function<_Tp>>::value,
822 bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
823 struct __is_destructible_safe;
825 template<typename _Tp>
826 struct __is_destructible_safe<_Tp, false, false>
827 : public __is_destructible_impl<typename
828 remove_all_extents<_Tp>::type>::type
831 template<typename _Tp>
832 struct __is_destructible_safe<_Tp, true, false>
833 : public false_type { };
835 template<typename _Tp>
836 struct __is_destructible_safe<_Tp, false, true>
837 : public true_type { };
840 template<typename _Tp>
841 struct is_destructible
842 : public __is_destructible_safe<_Tp>::type
844 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
845 "template argument must be a complete class or an unbounded array");
848 // is_nothrow_destructible requires that is_destructible is
849 // satisfied as well. We realize that by mimicing the
850 // implementation of is_destructible but refer to noexcept(expr)
851 // instead of decltype(expr).
852 struct __do_is_nt_destructible_impl
854 template<typename _Tp>
855 static __bool_constant<noexcept(declval<_Tp&>().~_Tp())>
859 static false_type __test(...);
862 template<typename _Tp>
863 struct __is_nt_destructible_impl
864 : public __do_is_nt_destructible_impl
866 typedef decltype(__test<_Tp>(0)) type;
869 template<typename _Tp,
870 bool = __or_<is_void<_Tp>,
871 __is_array_unknown_bounds<_Tp>,
872 is_function<_Tp>>::value,
873 bool = __or_<is_reference<_Tp>, is_scalar<_Tp>>::value>
874 struct __is_nt_destructible_safe;
876 template<typename _Tp>
877 struct __is_nt_destructible_safe<_Tp, false, false>
878 : public __is_nt_destructible_impl<typename
879 remove_all_extents<_Tp>::type>::type
882 template<typename _Tp>
883 struct __is_nt_destructible_safe<_Tp, true, false>
884 : public false_type { };
886 template<typename _Tp>
887 struct __is_nt_destructible_safe<_Tp, false, true>
888 : public true_type { };
890 /// is_nothrow_destructible
891 template<typename _Tp>
892 struct is_nothrow_destructible
893 : public __is_nt_destructible_safe<_Tp>::type
895 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
896 "template argument must be a complete class or an unbounded array");
899 template<typename _Tp, typename... _Args>
900 struct __is_constructible_impl
901 : public __bool_constant<__is_constructible(_Tp, _Args...)>
905 template<typename _Tp, typename... _Args>
906 struct is_constructible
907 : public __is_constructible_impl<_Tp, _Args...>
909 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
910 "template argument must be a complete class or an unbounded array");
913 /// is_default_constructible
914 template<typename _Tp>
915 struct is_default_constructible
916 : public __is_constructible_impl<_Tp>::type
918 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
919 "template argument must be a complete class or an unbounded array");
922 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
923 struct __is_copy_constructible_impl;
925 template<typename _Tp>
926 struct __is_copy_constructible_impl<_Tp, false>
927 : public false_type { };
929 template<typename _Tp>
930 struct __is_copy_constructible_impl<_Tp, true>
931 : public __is_constructible_impl<_Tp, const _Tp&>
934 /// is_copy_constructible
935 template<typename _Tp>
936 struct is_copy_constructible
937 : public __is_copy_constructible_impl<_Tp>
939 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
940 "template argument must be a complete class or an unbounded array");
943 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
944 struct __is_move_constructible_impl;
946 template<typename _Tp>
947 struct __is_move_constructible_impl<_Tp, false>
948 : public false_type { };
950 template<typename _Tp>
951 struct __is_move_constructible_impl<_Tp, true>
952 : public __is_constructible_impl<_Tp, _Tp&&>
955 /// is_move_constructible
956 template<typename _Tp>
957 struct is_move_constructible
958 : public __is_move_constructible_impl<_Tp>
960 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
961 "template argument must be a complete class or an unbounded array");
964 template<bool, typename _Tp, typename... _Args>
965 struct __is_nt_constructible_impl
969 template<typename _Tp, typename... _Args>
970 struct __is_nt_constructible_impl<true, _Tp, _Args...>
971 : public __bool_constant<noexcept(_Tp(std::declval<_Args>()...))>
974 template<typename _Tp, typename _Arg>
975 struct __is_nt_constructible_impl<true, _Tp, _Arg>
976 : public __bool_constant<noexcept(static_cast<_Tp>(std::declval<_Arg>()))>
979 template<typename _Tp>
980 struct __is_nt_constructible_impl<true, _Tp>
981 : public __bool_constant<noexcept(_Tp())>
984 template<typename _Tp, size_t _Num>
985 struct __is_nt_constructible_impl<true, _Tp[_Num]>
986 : public __bool_constant<noexcept(typename remove_all_extents<_Tp>::type())>
989 template<typename _Tp, typename... _Args>
990 using __is_nothrow_constructible_impl
991 = __is_nt_constructible_impl<__is_constructible(_Tp, _Args...),
994 /// is_nothrow_constructible
995 template<typename _Tp, typename... _Args>
996 struct is_nothrow_constructible
997 : public __is_nothrow_constructible_impl<_Tp, _Args...>::type
999 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1000 "template argument must be a complete class or an unbounded array");
1003 /// is_nothrow_default_constructible
1004 template<typename _Tp>
1005 struct is_nothrow_default_constructible
1006 : public __is_nothrow_constructible_impl<_Tp>::type
1008 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1009 "template argument must be a complete class or an unbounded array");
1013 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1014 struct __is_nothrow_copy_constructible_impl;
1016 template<typename _Tp>
1017 struct __is_nothrow_copy_constructible_impl<_Tp, false>
1018 : public false_type { };
1020 template<typename _Tp>
1021 struct __is_nothrow_copy_constructible_impl<_Tp, true>
1022 : public __is_nothrow_constructible_impl<_Tp, const _Tp&>
1025 /// is_nothrow_copy_constructible
1026 template<typename _Tp>
1027 struct is_nothrow_copy_constructible
1028 : public __is_nothrow_copy_constructible_impl<_Tp>::type
1030 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1031 "template argument must be a complete class or an unbounded array");
1034 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1035 struct __is_nothrow_move_constructible_impl;
1037 template<typename _Tp>
1038 struct __is_nothrow_move_constructible_impl<_Tp, false>
1039 : public false_type { };
1041 template<typename _Tp>
1042 struct __is_nothrow_move_constructible_impl<_Tp, true>
1043 : public __is_nothrow_constructible_impl<_Tp, _Tp&&>
1046 /// is_nothrow_move_constructible
1047 template<typename _Tp>
1048 struct is_nothrow_move_constructible
1049 : public __is_nothrow_move_constructible_impl<_Tp>::type
1051 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1052 "template argument must be a complete class or an unbounded array");
1056 template<typename _Tp, typename _Up>
1057 struct is_assignable
1058 : public __bool_constant<__is_assignable(_Tp, _Up)>
1060 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1061 "template argument must be a complete class or an unbounded array");
1064 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1065 struct __is_copy_assignable_impl;
1067 template<typename _Tp>
1068 struct __is_copy_assignable_impl<_Tp, false>
1069 : public false_type { };
1071 template<typename _Tp>
1072 struct __is_copy_assignable_impl<_Tp, true>
1073 : public __bool_constant<__is_assignable(_Tp&, const _Tp&)>
1076 /// is_copy_assignable
1077 template<typename _Tp>
1078 struct is_copy_assignable
1079 : public __is_copy_assignable_impl<_Tp>::type
1081 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1082 "template argument must be a complete class or an unbounded array");
1085 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1086 struct __is_move_assignable_impl;
1088 template<typename _Tp>
1089 struct __is_move_assignable_impl<_Tp, false>
1090 : public false_type { };
1092 template<typename _Tp>
1093 struct __is_move_assignable_impl<_Tp, true>
1094 : public __bool_constant<__is_assignable(_Tp&, _Tp&&)>
1097 /// is_move_assignable
1098 template<typename _Tp>
1099 struct is_move_assignable
1100 : public __is_move_assignable_impl<_Tp>::type
1102 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1103 "template argument must be a complete class or an unbounded array");
1106 template<typename _Tp, typename _Up>
1107 struct __is_nt_assignable_impl
1108 : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Up>())>
1111 template<typename _Tp, typename _Up>
1112 struct __is_nothrow_assignable_impl
1113 : public __and_<__bool_constant<__is_assignable(_Tp, _Up)>,
1114 __is_nt_assignable_impl<_Tp, _Up>>
1117 /// is_nothrow_assignable
1118 template<typename _Tp, typename _Up>
1119 struct is_nothrow_assignable
1120 : public __is_nothrow_assignable_impl<_Tp, _Up>
1122 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1123 "template argument must be a complete class or an unbounded array");
1126 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1127 struct __is_nt_copy_assignable_impl;
1129 template<typename _Tp>
1130 struct __is_nt_copy_assignable_impl<_Tp, false>
1131 : public false_type { };
1133 template<typename _Tp>
1134 struct __is_nt_copy_assignable_impl<_Tp, true>
1135 : public __is_nothrow_assignable_impl<_Tp&, const _Tp&>
1138 /// is_nothrow_copy_assignable
1139 template<typename _Tp>
1140 struct is_nothrow_copy_assignable
1141 : public __is_nt_copy_assignable_impl<_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 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1148 struct __is_nt_move_assignable_impl;
1150 template<typename _Tp>
1151 struct __is_nt_move_assignable_impl<_Tp, false>
1152 : public false_type { };
1154 template<typename _Tp>
1155 struct __is_nt_move_assignable_impl<_Tp, true>
1156 : public __is_nothrow_assignable_impl<_Tp&, _Tp&&>
1159 /// is_nothrow_move_assignable
1160 template<typename _Tp>
1161 struct is_nothrow_move_assignable
1162 : public __is_nt_move_assignable_impl<_Tp>
1164 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1165 "template argument must be a complete class or an unbounded array");
1168 /// is_trivially_constructible
1169 template<typename _Tp, typename... _Args>
1170 struct is_trivially_constructible
1171 : public __bool_constant<__is_trivially_constructible(_Tp, _Args...)>
1173 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1174 "template argument must be a complete class or an unbounded array");
1177 /// is_trivially_default_constructible
1178 template<typename _Tp>
1179 struct is_trivially_default_constructible
1180 : public __bool_constant<__is_trivially_constructible(_Tp)>
1182 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1183 "template argument must be a complete class or an unbounded array");
1186 struct __do_is_implicitly_default_constructible_impl
1188 template <typename _Tp>
1189 static void __helper(const _Tp&);
1191 template <typename _Tp>
1192 static true_type __test(const _Tp&,
1193 decltype(__helper<const _Tp&>({}))* = 0);
1195 static false_type __test(...);
1198 template<typename _Tp>
1199 struct __is_implicitly_default_constructible_impl
1200 : public __do_is_implicitly_default_constructible_impl
1202 typedef decltype(__test(declval<_Tp>())) type;
1205 template<typename _Tp>
1206 struct __is_implicitly_default_constructible_safe
1207 : public __is_implicitly_default_constructible_impl<_Tp>::type
1210 template <typename _Tp>
1211 struct __is_implicitly_default_constructible
1212 : public __and_<__is_constructible_impl<_Tp>,
1213 __is_implicitly_default_constructible_safe<_Tp>>
1216 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1217 struct __is_trivially_copy_constructible_impl;
1219 template<typename _Tp>
1220 struct __is_trivially_copy_constructible_impl<_Tp, false>
1221 : public false_type { };
1223 template<typename _Tp>
1224 struct __is_trivially_copy_constructible_impl<_Tp, true>
1225 : public __and_<__is_copy_constructible_impl<_Tp>,
1226 integral_constant<bool,
1227 __is_trivially_constructible(_Tp, const _Tp&)>>
1230 /// is_trivially_copy_constructible
1231 template<typename _Tp>
1232 struct is_trivially_copy_constructible
1233 : public __is_trivially_copy_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 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1240 struct __is_trivially_move_constructible_impl;
1242 template<typename _Tp>
1243 struct __is_trivially_move_constructible_impl<_Tp, false>
1244 : public false_type { };
1246 template<typename _Tp>
1247 struct __is_trivially_move_constructible_impl<_Tp, true>
1248 : public __and_<__is_move_constructible_impl<_Tp>,
1249 integral_constant<bool,
1250 __is_trivially_constructible(_Tp, _Tp&&)>>
1253 /// is_trivially_move_constructible
1254 template<typename _Tp>
1255 struct is_trivially_move_constructible
1256 : public __is_trivially_move_constructible_impl<_Tp>
1258 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1259 "template argument must be a complete class or an unbounded array");
1262 /// is_trivially_assignable
1263 template<typename _Tp, typename _Up>
1264 struct is_trivially_assignable
1265 : public __bool_constant<__is_trivially_assignable(_Tp, _Up)>
1267 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1268 "template argument must be a complete class or an unbounded array");
1271 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1272 struct __is_trivially_copy_assignable_impl;
1274 template<typename _Tp>
1275 struct __is_trivially_copy_assignable_impl<_Tp, false>
1276 : public false_type { };
1278 template<typename _Tp>
1279 struct __is_trivially_copy_assignable_impl<_Tp, true>
1280 : public __bool_constant<__is_trivially_assignable(_Tp&, const _Tp&)>
1283 /// is_trivially_copy_assignable
1284 template<typename _Tp>
1285 struct is_trivially_copy_assignable
1286 : public __is_trivially_copy_assignable_impl<_Tp>
1288 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1289 "template argument must be a complete class or an unbounded array");
1292 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1293 struct __is_trivially_move_assignable_impl;
1295 template<typename _Tp>
1296 struct __is_trivially_move_assignable_impl<_Tp, false>
1297 : public false_type { };
1299 template<typename _Tp>
1300 struct __is_trivially_move_assignable_impl<_Tp, true>
1301 : public __bool_constant<__is_trivially_assignable(_Tp&, _Tp&&)>
1304 /// is_trivially_move_assignable
1305 template<typename _Tp>
1306 struct is_trivially_move_assignable
1307 : public __is_trivially_move_assignable_impl<_Tp>
1309 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1310 "template argument must be a complete class or an unbounded array");
1313 /// is_trivially_destructible
1314 template<typename _Tp>
1315 struct is_trivially_destructible
1316 : public __and_<__is_destructible_safe<_Tp>,
1317 __bool_constant<__has_trivial_destructor(_Tp)>>
1319 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1320 "template argument must be a complete class or an unbounded array");
1324 /// has_virtual_destructor
1325 template<typename _Tp>
1326 struct has_virtual_destructor
1327 : public integral_constant<bool, __has_virtual_destructor(_Tp)>
1329 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1330 "template argument must be a complete class or an unbounded array");
1334 // type property queries.
1337 template<typename _Tp>
1339 : public integral_constant<std::size_t, alignof(_Tp)>
1341 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
1342 "template argument must be a complete class or an unbounded array");
1348 : public integral_constant<std::size_t, 0> { };
1350 template<typename _Tp, std::size_t _Size>
1351 struct rank<_Tp[_Size]>
1352 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1354 template<typename _Tp>
1356 : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
1359 template<typename, unsigned _Uint>
1361 : public integral_constant<std::size_t, 0> { };
1363 template<typename _Tp, unsigned _Uint, std::size_t _Size>
1364 struct extent<_Tp[_Size], _Uint>
1365 : public integral_constant<std::size_t,
1366 _Uint == 0 ? _Size : extent<_Tp,
1370 template<typename _Tp, unsigned _Uint>
1371 struct extent<_Tp[], _Uint>
1372 : public integral_constant<std::size_t,
1373 _Uint == 0 ? 0 : extent<_Tp,
1381 template<typename _Tp, typename _Up>
1383 #ifdef _GLIBCXX_BUILTIN_IS_SAME_AS
1384 : public integral_constant<bool, _GLIBCXX_BUILTIN_IS_SAME_AS(_Tp, _Up)>
1390 #ifndef _GLIBCXX_BUILTIN_IS_SAME_AS
1391 template<typename _Tp>
1392 struct is_same<_Tp, _Tp>
1398 template<typename _Base, typename _Derived>
1400 : public integral_constant<bool, __is_base_of(_Base, _Derived)>
1403 template<typename _From, typename _To,
1404 bool = __or_<is_void<_From>, is_function<_To>,
1405 is_array<_To>>::value>
1406 struct __is_convertible_helper
1408 typedef typename is_void<_To>::type type;
1411 #pragma GCC diagnostic push
1412 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
1413 template<typename _From, typename _To>
1414 class __is_convertible_helper<_From, _To, false>
1416 template<typename _To1>
1417 static void __test_aux(_To1) noexcept;
1419 template<typename _From1, typename _To1,
1420 typename = decltype(__test_aux<_To1>(std::declval<_From1>()))>
1424 template<typename, typename>
1429 typedef decltype(__test<_From, _To>(0)) type;
1431 #pragma GCC diagnostic pop
1434 template<typename _From, typename _To>
1435 struct is_convertible
1436 : public __is_convertible_helper<_From, _To>::type
1439 template<typename _From, typename _To,
1440 bool = __or_<is_void<_From>, is_function<_To>,
1441 is_array<_To>>::value>
1442 struct __is_nt_convertible_helper
1446 #pragma GCC diagnostic push
1447 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
1448 template<typename _From, typename _To>
1449 class __is_nt_convertible_helper<_From, _To, false>
1451 template<typename _To1>
1452 static void __test_aux(_To1) noexcept;
1454 template<typename _From1, typename _To1>
1456 __bool_constant<noexcept(__test_aux<_To1>(std::declval<_From1>()))>
1459 template<typename, typename>
1464 using type = decltype(__test<_From, _To>(0));
1466 #pragma GCC diagnostic pop
1468 // helper trait for unique_ptr<T[]>, shared_ptr<T[]>, and span<T, N>
1469 template<typename _ToElementType, typename _FromElementType>
1470 using __is_array_convertible
1471 = is_convertible<_FromElementType(*)[], _ToElementType(*)[]>;
1473 // is_nothrow_convertible for C++11
1474 template<typename _From, typename _To>
1475 struct __is_nothrow_convertible
1476 : public __is_nt_convertible_helper<_From, _To>::type
1479 #if __cplusplus > 201703L
1480 /// is_nothrow_convertible
1481 template<typename _From, typename _To>
1482 struct is_nothrow_convertible
1483 : public __is_nt_convertible_helper<_From, _To>::type
1486 /// is_nothrow_convertible_v
1487 template<typename _From, typename _To>
1488 inline constexpr bool is_nothrow_convertible_v
1489 = is_nothrow_convertible<_From, _To>::value;
1492 // Const-volatile modifications.
1495 template<typename _Tp>
1497 { typedef _Tp type; };
1499 template<typename _Tp>
1500 struct remove_const<_Tp const>
1501 { typedef _Tp type; };
1504 template<typename _Tp>
1505 struct remove_volatile
1506 { typedef _Tp type; };
1508 template<typename _Tp>
1509 struct remove_volatile<_Tp volatile>
1510 { typedef _Tp type; };
1513 template<typename _Tp>
1515 { using type = _Tp; };
1517 template<typename _Tp>
1518 struct remove_cv<const _Tp>
1519 { using type = _Tp; };
1521 template<typename _Tp>
1522 struct remove_cv<volatile _Tp>
1523 { using type = _Tp; };
1525 template<typename _Tp>
1526 struct remove_cv<const volatile _Tp>
1527 { using type = _Tp; };
1530 template<typename _Tp>
1532 { typedef _Tp const type; };
1535 template<typename _Tp>
1537 { typedef _Tp volatile type; };
1540 template<typename _Tp>
1544 add_const<typename add_volatile<_Tp>::type>::type type;
1547 #if __cplusplus > 201103L
1549 #define __cpp_lib_transformation_trait_aliases 201304
1551 /// Alias template for remove_const
1552 template<typename _Tp>
1553 using remove_const_t = typename remove_const<_Tp>::type;
1555 /// Alias template for remove_volatile
1556 template<typename _Tp>
1557 using remove_volatile_t = typename remove_volatile<_Tp>::type;
1559 /// Alias template for remove_cv
1560 template<typename _Tp>
1561 using remove_cv_t = typename remove_cv<_Tp>::type;
1563 /// Alias template for add_const
1564 template<typename _Tp>
1565 using add_const_t = typename add_const<_Tp>::type;
1567 /// Alias template for add_volatile
1568 template<typename _Tp>
1569 using add_volatile_t = typename add_volatile<_Tp>::type;
1571 /// Alias template for add_cv
1572 template<typename _Tp>
1573 using add_cv_t = typename add_cv<_Tp>::type;
1576 // Reference transformations.
1578 /// remove_reference
1579 template<typename _Tp>
1580 struct remove_reference
1581 { typedef _Tp type; };
1583 template<typename _Tp>
1584 struct remove_reference<_Tp&>
1585 { typedef _Tp type; };
1587 template<typename _Tp>
1588 struct remove_reference<_Tp&&>
1589 { typedef _Tp type; };
1591 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1592 struct __add_lvalue_reference_helper
1593 { typedef _Tp type; };
1595 template<typename _Tp>
1596 struct __add_lvalue_reference_helper<_Tp, true>
1597 { typedef _Tp& type; };
1599 /// add_lvalue_reference
1600 template<typename _Tp>
1601 struct add_lvalue_reference
1602 : public __add_lvalue_reference_helper<_Tp>
1605 template<typename _Tp, bool = __is_referenceable<_Tp>::value>
1606 struct __add_rvalue_reference_helper
1607 { typedef _Tp type; };
1609 template<typename _Tp>
1610 struct __add_rvalue_reference_helper<_Tp, true>
1611 { typedef _Tp&& type; };
1613 /// add_rvalue_reference
1614 template<typename _Tp>
1615 struct add_rvalue_reference
1616 : public __add_rvalue_reference_helper<_Tp>
1619 #if __cplusplus > 201103L
1620 /// Alias template for remove_reference
1621 template<typename _Tp>
1622 using remove_reference_t = typename remove_reference<_Tp>::type;
1624 /// Alias template for add_lvalue_reference
1625 template<typename _Tp>
1626 using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
1628 /// Alias template for add_rvalue_reference
1629 template<typename _Tp>
1630 using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
1633 // Sign modifications.
1635 // Utility for constructing identically cv-qualified types.
1636 template<typename _Unqualified, bool _IsConst, bool _IsVol>
1637 struct __cv_selector;
1639 template<typename _Unqualified>
1640 struct __cv_selector<_Unqualified, false, false>
1641 { typedef _Unqualified __type; };
1643 template<typename _Unqualified>
1644 struct __cv_selector<_Unqualified, false, true>
1645 { typedef volatile _Unqualified __type; };
1647 template<typename _Unqualified>
1648 struct __cv_selector<_Unqualified, true, false>
1649 { typedef const _Unqualified __type; };
1651 template<typename _Unqualified>
1652 struct __cv_selector<_Unqualified, true, true>
1653 { typedef const volatile _Unqualified __type; };
1655 template<typename _Qualified, typename _Unqualified,
1656 bool _IsConst = is_const<_Qualified>::value,
1657 bool _IsVol = is_volatile<_Qualified>::value>
1658 class __match_cv_qualifiers
1660 typedef __cv_selector<_Unqualified, _IsConst, _IsVol> __match;
1663 typedef typename __match::__type __type;
1666 // Utility for finding the unsigned versions of signed integral types.
1667 template<typename _Tp>
1668 struct __make_unsigned
1669 { typedef _Tp __type; };
1672 struct __make_unsigned<char>
1673 { typedef unsigned char __type; };
1676 struct __make_unsigned<signed char>
1677 { typedef unsigned char __type; };
1680 struct __make_unsigned<short>
1681 { typedef unsigned short __type; };
1684 struct __make_unsigned<int>
1685 { typedef unsigned int __type; };
1688 struct __make_unsigned<long>
1689 { typedef unsigned long __type; };
1692 struct __make_unsigned<long long>
1693 { typedef unsigned long long __type; };
1695 #if defined(__GLIBCXX_TYPE_INT_N_0)
1697 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_0>
1698 { typedef unsigned __GLIBCXX_TYPE_INT_N_0 __type; };
1700 #if defined(__GLIBCXX_TYPE_INT_N_1)
1702 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_1>
1703 { typedef unsigned __GLIBCXX_TYPE_INT_N_1 __type; };
1705 #if defined(__GLIBCXX_TYPE_INT_N_2)
1707 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_2>
1708 { typedef unsigned __GLIBCXX_TYPE_INT_N_2 __type; };
1710 #if defined(__GLIBCXX_TYPE_INT_N_3)
1712 struct __make_unsigned<__GLIBCXX_TYPE_INT_N_3>
1713 { typedef unsigned __GLIBCXX_TYPE_INT_N_3 __type; };
1716 // Select between integral and enum: not possible to be both.
1717 template<typename _Tp,
1718 bool _IsInt = is_integral<_Tp>::value,
1719 bool _IsEnum = is_enum<_Tp>::value>
1720 class __make_unsigned_selector;
1722 template<typename _Tp>
1723 class __make_unsigned_selector<_Tp, true, false>
1725 using __unsigned_type
1726 = typename __make_unsigned<__remove_cv_t<_Tp>>::__type;
1730 = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1733 class __make_unsigned_selector_base
1736 template<typename...> struct _List { };
1738 template<typename _Tp, typename... _Up>
1739 struct _List<_Tp, _Up...> : _List<_Up...>
1740 { static constexpr size_t __size = sizeof(_Tp); };
1742 template<size_t _Sz, typename _Tp, bool = (_Sz <= _Tp::__size)>
1745 template<size_t _Sz, typename _Uint, typename... _UInts>
1746 struct __select<_Sz, _List<_Uint, _UInts...>, true>
1747 { using __type = _Uint; };
1749 template<size_t _Sz, typename _Uint, typename... _UInts>
1750 struct __select<_Sz, _List<_Uint, _UInts...>, false>
1751 : __select<_Sz, _List<_UInts...>>
1755 // Choose unsigned integer type with the smallest rank and same size as _Tp
1756 template<typename _Tp>
1757 class __make_unsigned_selector<_Tp, false, true>
1758 : __make_unsigned_selector_base
1760 // With -fshort-enums, an enum may be as small as a char.
1761 using _UInts = _List<unsigned char, unsigned short, unsigned int,
1762 unsigned long, unsigned long long>;
1764 using __unsigned_type = typename __select<sizeof(_Tp), _UInts>::__type;
1768 = typename __match_cv_qualifiers<_Tp, __unsigned_type>::__type;
1771 // wchar_t, char8_t, char16_t and char32_t are integral types but are
1772 // neither signed integer types nor unsigned integer types, so must be
1773 // transformed to the unsigned integer type with the smallest rank.
1774 // Use the partial specialization for enumeration types to do that.
1775 #if defined(_GLIBCXX_USE_WCHAR_T)
1777 struct __make_unsigned<wchar_t>
1780 = typename __make_unsigned_selector<wchar_t, false, true>::__type;
1784 #ifdef _GLIBCXX_USE_CHAR8_T
1786 struct __make_unsigned<char8_t>
1789 = typename __make_unsigned_selector<char8_t, false, true>::__type;
1794 struct __make_unsigned<char16_t>
1797 = typename __make_unsigned_selector<char16_t, false, true>::__type;
1801 struct __make_unsigned<char32_t>
1804 = typename __make_unsigned_selector<char32_t, false, true>::__type;
1807 // Given an integral/enum type, return the corresponding unsigned
1809 // Primary template.
1811 template<typename _Tp>
1812 struct make_unsigned
1813 { typedef typename __make_unsigned_selector<_Tp>::__type type; };
1815 // Integral, but don't define.
1817 struct make_unsigned<bool>;
1820 // Utility for finding the signed versions of unsigned integral types.
1821 template<typename _Tp>
1822 struct __make_signed
1823 { typedef _Tp __type; };
1826 struct __make_signed<char>
1827 { typedef signed char __type; };
1830 struct __make_signed<unsigned char>
1831 { typedef signed char __type; };
1834 struct __make_signed<unsigned short>
1835 { typedef signed short __type; };
1838 struct __make_signed<unsigned int>
1839 { typedef signed int __type; };
1842 struct __make_signed<unsigned long>
1843 { typedef signed long __type; };
1846 struct __make_signed<unsigned long long>
1847 { typedef signed long long __type; };
1849 #if defined(__GLIBCXX_TYPE_INT_N_0)
1851 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_0>
1852 { typedef __GLIBCXX_TYPE_INT_N_0 __type; };
1854 #if defined(__GLIBCXX_TYPE_INT_N_1)
1856 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_1>
1857 { typedef __GLIBCXX_TYPE_INT_N_1 __type; };
1859 #if defined(__GLIBCXX_TYPE_INT_N_2)
1861 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_2>
1862 { typedef __GLIBCXX_TYPE_INT_N_2 __type; };
1864 #if defined(__GLIBCXX_TYPE_INT_N_3)
1866 struct __make_signed<unsigned __GLIBCXX_TYPE_INT_N_3>
1867 { typedef __GLIBCXX_TYPE_INT_N_3 __type; };
1870 // Select between integral and enum: not possible to be both.
1871 template<typename _Tp,
1872 bool _IsInt = is_integral<_Tp>::value,
1873 bool _IsEnum = is_enum<_Tp>::value>
1874 class __make_signed_selector;
1876 template<typename _Tp>
1877 class __make_signed_selector<_Tp, true, false>
1880 = typename __make_signed<__remove_cv_t<_Tp>>::__type;
1884 = typename __match_cv_qualifiers<_Tp, __signed_type>::__type;
1887 // Choose signed integer type with the smallest rank and same size as _Tp
1888 template<typename _Tp>
1889 class __make_signed_selector<_Tp, false, true>
1891 typedef typename __make_unsigned_selector<_Tp>::__type __unsigned_type;
1894 typedef typename __make_signed_selector<__unsigned_type>::__type __type;
1897 // wchar_t, char16_t and char32_t are integral types but are neither
1898 // signed integer types nor unsigned integer types, so must be
1899 // transformed to the signed integer type with the smallest rank.
1900 // Use the partial specialization for enumeration types to do that.
1901 #if defined(_GLIBCXX_USE_WCHAR_T)
1903 struct __make_signed<wchar_t>
1906 = typename __make_signed_selector<wchar_t, false, true>::__type;
1910 #if defined(_GLIBCXX_USE_CHAR8_T)
1912 struct __make_signed<char8_t>
1915 = typename __make_signed_selector<char8_t, false, true>::__type;
1920 struct __make_signed<char16_t>
1923 = typename __make_signed_selector<char16_t, false, true>::__type;
1927 struct __make_signed<char32_t>
1930 = typename __make_signed_selector<char32_t, false, true>::__type;
1933 // Given an integral/enum type, return the corresponding signed
1935 // Primary template.
1937 template<typename _Tp>
1939 { typedef typename __make_signed_selector<_Tp>::__type type; };
1941 // Integral, but don't define.
1943 struct make_signed<bool>;
1945 #if __cplusplus > 201103L
1946 /// Alias template for make_signed
1947 template<typename _Tp>
1948 using make_signed_t = typename make_signed<_Tp>::type;
1950 /// Alias template for make_unsigned
1951 template<typename _Tp>
1952 using make_unsigned_t = typename make_unsigned<_Tp>::type;
1955 // Array modifications.
1958 template<typename _Tp>
1959 struct remove_extent
1960 { typedef _Tp type; };
1962 template<typename _Tp, std::size_t _Size>
1963 struct remove_extent<_Tp[_Size]>
1964 { typedef _Tp type; };
1966 template<typename _Tp>
1967 struct remove_extent<_Tp[]>
1968 { typedef _Tp type; };
1970 /// remove_all_extents
1971 template<typename _Tp>
1972 struct remove_all_extents
1973 { typedef _Tp type; };
1975 template<typename _Tp, std::size_t _Size>
1976 struct remove_all_extents<_Tp[_Size]>
1977 { typedef typename remove_all_extents<_Tp>::type type; };
1979 template<typename _Tp>
1980 struct remove_all_extents<_Tp[]>
1981 { typedef typename remove_all_extents<_Tp>::type type; };
1983 #if __cplusplus > 201103L
1984 /// Alias template for remove_extent
1985 template<typename _Tp>
1986 using remove_extent_t = typename remove_extent<_Tp>::type;
1988 /// Alias template for remove_all_extents
1989 template<typename _Tp>
1990 using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
1993 // Pointer modifications.
1995 template<typename _Tp, typename>
1996 struct __remove_pointer_helper
1997 { typedef _Tp type; };
1999 template<typename _Tp, typename _Up>
2000 struct __remove_pointer_helper<_Tp, _Up*>
2001 { typedef _Up type; };
2004 template<typename _Tp>
2005 struct remove_pointer
2006 : public __remove_pointer_helper<_Tp, __remove_cv_t<_Tp>>
2010 template<typename _Tp, bool = __or_<__is_referenceable<_Tp>,
2011 is_void<_Tp>>::value>
2012 struct __add_pointer_helper
2013 { typedef _Tp type; };
2015 template<typename _Tp>
2016 struct __add_pointer_helper<_Tp, true>
2017 { typedef typename remove_reference<_Tp>::type* type; };
2019 template<typename _Tp>
2021 : public __add_pointer_helper<_Tp>
2024 #if __cplusplus > 201103L
2025 /// Alias template for remove_pointer
2026 template<typename _Tp>
2027 using remove_pointer_t = typename remove_pointer<_Tp>::type;
2029 /// Alias template for add_pointer
2030 template<typename _Tp>
2031 using add_pointer_t = typename add_pointer<_Tp>::type;
2034 template<std::size_t _Len>
2035 struct __aligned_storage_msa
2039 unsigned char __data[_Len];
2040 struct __attribute__((__aligned__)) { } __align;
2045 * @brief Alignment type.
2047 * The value of _Align is a default-alignment which shall be the
2048 * most stringent alignment requirement for any C++ object type
2049 * whose size is no greater than _Len (3.9). The member typedef
2050 * type shall be a POD type suitable for use as uninitialized
2051 * storage for any object whose size is at most _Len and whose
2052 * alignment is a divisor of _Align.
2054 template<std::size_t _Len, std::size_t _Align =
2055 __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2056 struct aligned_storage
2060 unsigned char __data[_Len];
2061 struct __attribute__((__aligned__((_Align)))) { } __align;
2065 template <typename... _Types>
2066 struct __strictest_alignment
2068 static const size_t _S_alignment = 0;
2069 static const size_t _S_size = 0;
2072 template <typename _Tp, typename... _Types>
2073 struct __strictest_alignment<_Tp, _Types...>
2075 static const size_t _S_alignment =
2076 alignof(_Tp) > __strictest_alignment<_Types...>::_S_alignment
2077 ? alignof(_Tp) : __strictest_alignment<_Types...>::_S_alignment;
2078 static const size_t _S_size =
2079 sizeof(_Tp) > __strictest_alignment<_Types...>::_S_size
2080 ? sizeof(_Tp) : __strictest_alignment<_Types...>::_S_size;
2084 * @brief Provide aligned storage for types.
2086 * [meta.trans.other]
2088 * Provides aligned storage for any of the provided types of at
2091 * @see aligned_storage
2093 template <size_t _Len, typename... _Types>
2094 struct aligned_union
2097 static_assert(sizeof...(_Types) != 0, "At least one type is required");
2099 using __strictest = __strictest_alignment<_Types...>;
2100 static const size_t _S_len = _Len > __strictest::_S_size
2101 ? _Len : __strictest::_S_size;
2103 /// The value of the strictest alignment of _Types.
2104 static const size_t alignment_value = __strictest::_S_alignment;
2106 typedef typename aligned_storage<_S_len, alignment_value>::type type;
2109 template <size_t _Len, typename... _Types>
2110 const size_t aligned_union<_Len, _Types...>::alignment_value;
2112 // Decay trait for arrays and functions, used for perfect forwarding
2113 // in make_pair, make_tuple, etc.
2114 template<typename _Up,
2115 bool _IsArray = is_array<_Up>::value,
2116 bool _IsFunction = is_function<_Up>::value>
2117 struct __decay_selector;
2120 template<typename _Up>
2121 struct __decay_selector<_Up, false, false>
2122 { typedef __remove_cv_t<_Up> __type; };
2124 template<typename _Up>
2125 struct __decay_selector<_Up, true, false>
2126 { typedef typename remove_extent<_Up>::type* __type; };
2128 template<typename _Up>
2129 struct __decay_selector<_Up, false, true>
2130 { typedef typename add_pointer<_Up>::type __type; };
2133 template<typename _Tp>
2136 typedef typename remove_reference<_Tp>::type __remove_type;
2139 typedef typename __decay_selector<__remove_type>::__type type;
2142 // __decay_t (std::decay_t for C++11).
2143 template<typename _Tp>
2144 using __decay_t = typename decay<_Tp>::type;
2146 template<typename _Tp>
2147 class reference_wrapper;
2149 // Helper which adds a reference to a type when given a reference_wrapper
2150 template<typename _Tp>
2151 struct __strip_reference_wrapper
2156 template<typename _Tp>
2157 struct __strip_reference_wrapper<reference_wrapper<_Tp> >
2159 typedef _Tp& __type;
2162 template<typename _Tp>
2163 using __decay_and_strip = __strip_reference_wrapper<__decay_t<_Tp>>;
2166 // Primary template.
2167 /// Define a member typedef @c type only if a boolean constant is true.
2168 template<bool, typename _Tp = void>
2172 // Partial specialization for true.
2173 template<typename _Tp>
2174 struct enable_if<true, _Tp>
2175 { typedef _Tp type; };
2177 // __enable_if_t (std::enable_if_t for C++11)
2178 template<bool _Cond, typename _Tp = void>
2179 using __enable_if_t = typename enable_if<_Cond, _Tp>::type;
2181 template<typename... _Cond>
2182 using _Require = __enable_if_t<__and_<_Cond...>::value>;
2184 // Primary template.
2185 /// Define a member typedef @c type to one of two argument types.
2186 template<bool _Cond, typename _Iftrue, typename _Iffalse>
2188 { typedef _Iftrue type; };
2190 // Partial specialization for false.
2191 template<typename _Iftrue, typename _Iffalse>
2192 struct conditional<false, _Iftrue, _Iffalse>
2193 { typedef _Iffalse type; };
2195 // __remove_cvref_t (std::remove_cvref_t for C++11).
2196 template<typename _Tp>
2197 using __remove_cvref_t
2198 = typename remove_cv<typename remove_reference<_Tp>::type>::type;
2201 template<typename... _Tp>
2204 // Sfinae-friendly common_type implementation:
2206 struct __do_common_type_impl
2208 template<typename _Tp, typename _Up>
2210 = decltype(true ? std::declval<_Tp>() : std::declval<_Up>());
2212 // if decay_t<decltype(false ? declval<D1>() : declval<D2>())>
2213 // denotes a valid type, let C denote that type.
2214 template<typename _Tp, typename _Up>
2215 static __success_type<__decay_t<__cond_t<_Tp, _Up>>>
2218 #if __cplusplus > 201703L
2219 // Otherwise, if COND-RES(CREF(D1), CREF(D2)) denotes a type,
2220 // let C denote the type decay_t<COND-RES(CREF(D1), CREF(D2))>.
2221 template<typename _Tp, typename _Up>
2222 static __success_type<__remove_cvref_t<__cond_t<const _Tp&, const _Up&>>>
2226 template<typename, typename>
2227 static __failure_type
2230 template<typename _Tp, typename _Up>
2231 static decltype(_S_test_2<_Tp, _Up>(0))
2235 // If sizeof...(T) is zero, there shall be no member type.
2237 struct common_type<>
2240 // If sizeof...(T) is one, the same type, if any, as common_type_t<T0, T0>.
2241 template<typename _Tp0>
2242 struct common_type<_Tp0>
2243 : public common_type<_Tp0, _Tp0>
2246 // If sizeof...(T) is two, ...
2247 template<typename _Tp1, typename _Tp2,
2248 typename _Dp1 = __decay_t<_Tp1>, typename _Dp2 = __decay_t<_Tp2>>
2249 struct __common_type_impl
2251 // If is_same_v<T1, D1> is false or is_same_v<T2, D2> is false,
2252 // let C denote the same type, if any, as common_type_t<D1, D2>.
2253 using type = common_type<_Dp1, _Dp2>;
2256 template<typename _Tp1, typename _Tp2>
2257 struct __common_type_impl<_Tp1, _Tp2, _Tp1, _Tp2>
2258 : private __do_common_type_impl
2260 // Otherwise, if decay_t<decltype(false ? declval<D1>() : declval<D2>())>
2261 // denotes a valid type, let C denote that type.
2262 using type = decltype(_S_test<_Tp1, _Tp2>(0));
2265 // If sizeof...(T) is two, ...
2266 template<typename _Tp1, typename _Tp2>
2267 struct common_type<_Tp1, _Tp2>
2268 : public __common_type_impl<_Tp1, _Tp2>::type
2271 template<typename...>
2272 struct __common_type_pack
2275 template<typename, typename, typename = void>
2276 struct __common_type_fold;
2278 // If sizeof...(T) is greater than two, ...
2279 template<typename _Tp1, typename _Tp2, typename... _Rp>
2280 struct common_type<_Tp1, _Tp2, _Rp...>
2281 : public __common_type_fold<common_type<_Tp1, _Tp2>,
2282 __common_type_pack<_Rp...>>
2285 // Let C denote the same type, if any, as common_type_t<T1, T2>.
2286 // If there is such a type C, type shall denote the same type, if any,
2287 // as common_type_t<C, R...>.
2288 template<typename _CTp, typename... _Rp>
2289 struct __common_type_fold<_CTp, __common_type_pack<_Rp...>,
2290 __void_t<typename _CTp::type>>
2291 : public common_type<typename _CTp::type, _Rp...>
2294 // Otherwise, there shall be no member type.
2295 template<typename _CTp, typename _Rp>
2296 struct __common_type_fold<_CTp, _Rp, void>
2299 template<typename _Tp, bool = is_enum<_Tp>::value>
2300 struct __underlying_type_impl
2302 using type = __underlying_type(_Tp);
2305 template<typename _Tp>
2306 struct __underlying_type_impl<_Tp, false>
2309 /// The underlying type of an enum.
2310 template<typename _Tp>
2311 struct underlying_type
2312 : public __underlying_type_impl<_Tp>
2315 template<typename _Tp>
2316 struct __declval_protector
2318 static const bool __stop = false;
2321 template<typename _Tp>
2322 auto declval() noexcept -> decltype(__declval<_Tp>(0))
2324 static_assert(__declval_protector<_Tp>::__stop,
2325 "declval() must not be used!");
2326 return __declval<_Tp>(0);
2330 template<typename _Signature>
2333 // Sfinae-friendly result_of implementation:
2335 #define __cpp_lib_result_of_sfinae 201210
2337 struct __invoke_memfun_ref { };
2338 struct __invoke_memfun_deref { };
2339 struct __invoke_memobj_ref { };
2340 struct __invoke_memobj_deref { };
2341 struct __invoke_other { };
2343 // Associate a tag type with a specialization of __success_type.
2344 template<typename _Tp, typename _Tag>
2345 struct __result_of_success : __success_type<_Tp>
2346 { using __invoke_type = _Tag; };
2348 // [func.require] paragraph 1 bullet 1:
2349 struct __result_of_memfun_ref_impl
2351 template<typename _Fp, typename _Tp1, typename... _Args>
2352 static __result_of_success<decltype(
2353 (std::declval<_Tp1>().*std::declval<_Fp>())(std::declval<_Args>()...)
2354 ), __invoke_memfun_ref> _S_test(int);
2356 template<typename...>
2357 static __failure_type _S_test(...);
2360 template<typename _MemPtr, typename _Arg, typename... _Args>
2361 struct __result_of_memfun_ref
2362 : private __result_of_memfun_ref_impl
2364 typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2367 // [func.require] paragraph 1 bullet 2:
2368 struct __result_of_memfun_deref_impl
2370 template<typename _Fp, typename _Tp1, typename... _Args>
2371 static __result_of_success<decltype(
2372 ((*std::declval<_Tp1>()).*std::declval<_Fp>())(std::declval<_Args>()...)
2373 ), __invoke_memfun_deref> _S_test(int);
2375 template<typename...>
2376 static __failure_type _S_test(...);
2379 template<typename _MemPtr, typename _Arg, typename... _Args>
2380 struct __result_of_memfun_deref
2381 : private __result_of_memfun_deref_impl
2383 typedef decltype(_S_test<_MemPtr, _Arg, _Args...>(0)) type;
2386 // [func.require] paragraph 1 bullet 3:
2387 struct __result_of_memobj_ref_impl
2389 template<typename _Fp, typename _Tp1>
2390 static __result_of_success<decltype(
2391 std::declval<_Tp1>().*std::declval<_Fp>()
2392 ), __invoke_memobj_ref> _S_test(int);
2394 template<typename, typename>
2395 static __failure_type _S_test(...);
2398 template<typename _MemPtr, typename _Arg>
2399 struct __result_of_memobj_ref
2400 : private __result_of_memobj_ref_impl
2402 typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2405 // [func.require] paragraph 1 bullet 4:
2406 struct __result_of_memobj_deref_impl
2408 template<typename _Fp, typename _Tp1>
2409 static __result_of_success<decltype(
2410 (*std::declval<_Tp1>()).*std::declval<_Fp>()
2411 ), __invoke_memobj_deref> _S_test(int);
2413 template<typename, typename>
2414 static __failure_type _S_test(...);
2417 template<typename _MemPtr, typename _Arg>
2418 struct __result_of_memobj_deref
2419 : private __result_of_memobj_deref_impl
2421 typedef decltype(_S_test<_MemPtr, _Arg>(0)) type;
2424 template<typename _MemPtr, typename _Arg>
2425 struct __result_of_memobj;
2427 template<typename _Res, typename _Class, typename _Arg>
2428 struct __result_of_memobj<_Res _Class::*, _Arg>
2430 typedef __remove_cvref_t<_Arg> _Argval;
2431 typedef _Res _Class::* _MemPtr;
2432 typedef typename conditional<__or_<is_same<_Argval, _Class>,
2433 is_base_of<_Class, _Argval>>::value,
2434 __result_of_memobj_ref<_MemPtr, _Arg>,
2435 __result_of_memobj_deref<_MemPtr, _Arg>
2439 template<typename _MemPtr, typename _Arg, typename... _Args>
2440 struct __result_of_memfun;
2442 template<typename _Res, typename _Class, typename _Arg, typename... _Args>
2443 struct __result_of_memfun<_Res _Class::*, _Arg, _Args...>
2445 typedef typename remove_reference<_Arg>::type _Argval;
2446 typedef _Res _Class::* _MemPtr;
2447 typedef typename conditional<is_base_of<_Class, _Argval>::value,
2448 __result_of_memfun_ref<_MemPtr, _Arg, _Args...>,
2449 __result_of_memfun_deref<_MemPtr, _Arg, _Args...>
2453 // _GLIBCXX_RESOLVE_LIB_DEFECTS
2454 // 2219. INVOKE-ing a pointer to member with a reference_wrapper
2455 // as the object expression
2457 // Used by result_of, invoke etc. to unwrap a reference_wrapper.
2458 template<typename _Tp, typename _Up = __remove_cvref_t<_Tp>>
2464 template<typename _Tp, typename _Up>
2465 struct __inv_unwrap<_Tp, reference_wrapper<_Up>>
2470 template<bool, bool, typename _Functor, typename... _ArgTypes>
2471 struct __result_of_impl
2473 typedef __failure_type type;
2476 template<typename _MemPtr, typename _Arg>
2477 struct __result_of_impl<true, false, _MemPtr, _Arg>
2478 : public __result_of_memobj<__decay_t<_MemPtr>,
2479 typename __inv_unwrap<_Arg>::type>
2482 template<typename _MemPtr, typename _Arg, typename... _Args>
2483 struct __result_of_impl<false, true, _MemPtr, _Arg, _Args...>
2484 : public __result_of_memfun<__decay_t<_MemPtr>,
2485 typename __inv_unwrap<_Arg>::type, _Args...>
2488 // [func.require] paragraph 1 bullet 5:
2489 struct __result_of_other_impl
2491 template<typename _Fn, typename... _Args>
2492 static __result_of_success<decltype(
2493 std::declval<_Fn>()(std::declval<_Args>()...)
2494 ), __invoke_other> _S_test(int);
2496 template<typename...>
2497 static __failure_type _S_test(...);
2500 template<typename _Functor, typename... _ArgTypes>
2501 struct __result_of_impl<false, false, _Functor, _ArgTypes...>
2502 : private __result_of_other_impl
2504 typedef decltype(_S_test<_Functor, _ArgTypes...>(0)) type;
2507 // __invoke_result (std::invoke_result for C++11)
2508 template<typename _Functor, typename... _ArgTypes>
2509 struct __invoke_result
2510 : public __result_of_impl<
2511 is_member_object_pointer<
2512 typename remove_reference<_Functor>::type
2514 is_member_function_pointer<
2515 typename remove_reference<_Functor>::type
2517 _Functor, _ArgTypes...
2521 template<typename _Functor, typename... _ArgTypes>
2522 struct result_of<_Functor(_ArgTypes...)>
2523 : public __invoke_result<_Functor, _ArgTypes...>
2526 #if __cplusplus >= 201402L
2527 /// Alias template for aligned_storage
2528 template<size_t _Len, size_t _Align =
2529 __alignof__(typename __aligned_storage_msa<_Len>::__type)>
2530 using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
2532 template <size_t _Len, typename... _Types>
2533 using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
2535 /// Alias template for decay
2536 template<typename _Tp>
2537 using decay_t = typename decay<_Tp>::type;
2539 /// Alias template for enable_if
2540 template<bool _Cond, typename _Tp = void>
2541 using enable_if_t = typename enable_if<_Cond, _Tp>::type;
2543 /// Alias template for conditional
2544 template<bool _Cond, typename _Iftrue, typename _Iffalse>
2545 using conditional_t = typename conditional<_Cond, _Iftrue, _Iffalse>::type;
2547 /// Alias template for common_type
2548 template<typename... _Tp>
2549 using common_type_t = typename common_type<_Tp...>::type;
2551 /// Alias template for underlying_type
2552 template<typename _Tp>
2553 using underlying_type_t = typename underlying_type<_Tp>::type;
2555 /// Alias template for result_of
2556 template<typename _Tp>
2557 using result_of_t = typename result_of<_Tp>::type;
2560 #if __cplusplus >= 201703L || !defined(__STRICT_ANSI__) // c++17 or gnu++11
2561 #define __cpp_lib_void_t 201411
2562 /// A metafunction that always yields void, used for detecting valid types.
2563 template<typename...> using void_t = void;
2566 /// Implementation of the detection idiom (negative case).
2567 template<typename _Default, typename _AlwaysVoid,
2568 template<typename...> class _Op, typename... _Args>
2571 using value_t = false_type;
2572 using type = _Default;
2575 /// Implementation of the detection idiom (positive case).
2576 template<typename _Default, template<typename...> class _Op,
2578 struct __detector<_Default, __void_t<_Op<_Args...>>, _Op, _Args...>
2580 using value_t = true_type;
2581 using type = _Op<_Args...>;
2584 // Detect whether _Op<_Args...> is a valid type, use _Default if not.
2585 template<typename _Default, template<typename...> class _Op,
2587 using __detected_or = __detector<_Default, void, _Op, _Args...>;
2589 // _Op<_Args...> if that is a valid type, otherwise _Default.
2590 template<typename _Default, template<typename...> class _Op,
2592 using __detected_or_t
2593 = typename __detected_or<_Default, _Op, _Args...>::type;
2595 /// @} group metaprogramming
2598 * Use SFINAE to determine if the type _Tp has a publicly-accessible
2599 * member type _NTYPE.
2601 #define _GLIBCXX_HAS_NESTED_TYPE(_NTYPE) \
2602 template<typename _Tp, typename = __void_t<>> \
2603 struct __has_##_NTYPE \
2606 template<typename _Tp> \
2607 struct __has_##_NTYPE<_Tp, __void_t<typename _Tp::_NTYPE>> \
2611 template <typename _Tp>
2612 struct __is_swappable;
2614 template <typename _Tp>
2615 struct __is_nothrow_swappable;
2617 template<typename... _Elements>
2621 struct __is_tuple_like_impl : false_type
2624 template<typename... _Tps>
2625 struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
2628 // Internal type trait that allows us to sfinae-protect tuple_cat.
2629 template<typename _Tp>
2630 struct __is_tuple_like
2631 : public __is_tuple_like_impl<__remove_cvref_t<_Tp>>::type
2634 template<typename _Tp>
2635 _GLIBCXX20_CONSTEXPR
2637 _Require<__not_<__is_tuple_like<_Tp>>,
2638 is_move_constructible<_Tp>,
2639 is_move_assignable<_Tp>>
2641 noexcept(__and_<is_nothrow_move_constructible<_Tp>,
2642 is_nothrow_move_assignable<_Tp>>::value);
2644 template<typename _Tp, size_t _Nm>
2645 _GLIBCXX20_CONSTEXPR
2647 __enable_if_t<__is_swappable<_Tp>::value>
2648 swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
2649 noexcept(__is_nothrow_swappable<_Tp>::value);
2651 namespace __swappable_details {
2654 struct __do_is_swappable_impl
2656 template<typename _Tp, typename
2657 = decltype(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))>
2658 static true_type __test(int);
2661 static false_type __test(...);
2664 struct __do_is_nothrow_swappable_impl
2666 template<typename _Tp>
2667 static __bool_constant<
2668 noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>()))
2672 static false_type __test(...);
2675 } // namespace __swappable_details
2677 template<typename _Tp>
2678 struct __is_swappable_impl
2679 : public __swappable_details::__do_is_swappable_impl
2681 typedef decltype(__test<_Tp>(0)) type;
2684 template<typename _Tp>
2685 struct __is_nothrow_swappable_impl
2686 : public __swappable_details::__do_is_nothrow_swappable_impl
2688 typedef decltype(__test<_Tp>(0)) type;
2691 template<typename _Tp>
2692 struct __is_swappable
2693 : public __is_swappable_impl<_Tp>::type
2696 template<typename _Tp>
2697 struct __is_nothrow_swappable
2698 : public __is_nothrow_swappable_impl<_Tp>::type
2701 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
2702 #define __cpp_lib_is_swappable 201603
2703 /// Metafunctions used for detecting swappable types: p0185r1
2706 template<typename _Tp>
2708 : public __is_swappable_impl<_Tp>::type
2710 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2711 "template argument must be a complete class or an unbounded array");
2714 /// is_nothrow_swappable
2715 template<typename _Tp>
2716 struct is_nothrow_swappable
2717 : public __is_nothrow_swappable_impl<_Tp>::type
2719 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
2720 "template argument must be a complete class or an unbounded array");
2723 #if __cplusplus >= 201402L
2725 template<typename _Tp>
2726 _GLIBCXX17_INLINE constexpr bool is_swappable_v =
2727 is_swappable<_Tp>::value;
2729 /// is_nothrow_swappable_v
2730 template<typename _Tp>
2731 _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_v =
2732 is_nothrow_swappable<_Tp>::value;
2733 #endif // __cplusplus >= 201402L
2735 namespace __swappable_with_details {
2738 struct __do_is_swappable_with_impl
2740 template<typename _Tp, typename _Up, typename
2741 = decltype(swap(std::declval<_Tp>(), std::declval<_Up>())),
2743 = decltype(swap(std::declval<_Up>(), std::declval<_Tp>()))>
2744 static true_type __test(int);
2746 template<typename, typename>
2747 static false_type __test(...);
2750 struct __do_is_nothrow_swappable_with_impl
2752 template<typename _Tp, typename _Up>
2753 static __bool_constant<
2754 noexcept(swap(std::declval<_Tp>(), std::declval<_Up>()))
2756 noexcept(swap(std::declval<_Up>(), std::declval<_Tp>()))
2759 template<typename, typename>
2760 static false_type __test(...);
2763 } // namespace __swappable_with_details
2765 template<typename _Tp, typename _Up>
2766 struct __is_swappable_with_impl
2767 : public __swappable_with_details::__do_is_swappable_with_impl
2769 typedef decltype(__test<_Tp, _Up>(0)) type;
2772 // Optimization for the homogenous lvalue case, not required:
2773 template<typename _Tp>
2774 struct __is_swappable_with_impl<_Tp&, _Tp&>
2775 : public __swappable_details::__do_is_swappable_impl
2777 typedef decltype(__test<_Tp&>(0)) type;
2780 template<typename _Tp, typename _Up>
2781 struct __is_nothrow_swappable_with_impl
2782 : public __swappable_with_details::__do_is_nothrow_swappable_with_impl
2784 typedef decltype(__test<_Tp, _Up>(0)) type;
2787 // Optimization for the homogenous lvalue case, not required:
2788 template<typename _Tp>
2789 struct __is_nothrow_swappable_with_impl<_Tp&, _Tp&>
2790 : public __swappable_details::__do_is_nothrow_swappable_impl
2792 typedef decltype(__test<_Tp&>(0)) type;
2795 /// is_swappable_with
2796 template<typename _Tp, typename _Up>
2797 struct is_swappable_with
2798 : public __is_swappable_with_impl<_Tp, _Up>::type
2801 /// is_nothrow_swappable_with
2802 template<typename _Tp, typename _Up>
2803 struct is_nothrow_swappable_with
2804 : public __is_nothrow_swappable_with_impl<_Tp, _Up>::type
2807 #if __cplusplus >= 201402L
2808 /// is_swappable_with_v
2809 template<typename _Tp, typename _Up>
2810 _GLIBCXX17_INLINE constexpr bool is_swappable_with_v =
2811 is_swappable_with<_Tp, _Up>::value;
2813 /// is_nothrow_swappable_with_v
2814 template<typename _Tp, typename _Up>
2815 _GLIBCXX17_INLINE constexpr bool is_nothrow_swappable_with_v =
2816 is_nothrow_swappable_with<_Tp, _Up>::value;
2817 #endif // __cplusplus >= 201402L
2819 #endif// c++1z or gnu++11
2821 // __is_invocable (std::is_invocable for C++11)
2823 // The primary template is used for invalid INVOKE expressions.
2824 template<typename _Result, typename _Ret,
2825 bool = is_void<_Ret>::value, typename = void>
2826 struct __is_invocable_impl : false_type { };
2828 // Used for valid INVOKE and INVOKE<void> expressions.
2829 template<typename _Result, typename _Ret>
2830 struct __is_invocable_impl<_Result, _Ret,
2831 /* is_void<_Ret> = */ true,
2832 __void_t<typename _Result::type>>
2836 #pragma GCC diagnostic push
2837 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
2838 // Used for INVOKE<R> expressions to check the implicit conversion to R.
2839 template<typename _Result, typename _Ret>
2840 struct __is_invocable_impl<_Result, _Ret,
2841 /* is_void<_Ret> = */ false,
2842 __void_t<typename _Result::type>>
2845 // The type of the INVOKE expression.
2846 // Unlike declval, this doesn't add_rvalue_reference.
2847 static typename _Result::type _S_get();
2849 template<typename _Tp>
2850 static void _S_conv(_Tp);
2852 // This overload is viable if INVOKE(f, args...) can convert to _Tp.
2853 template<typename _Tp, typename = decltype(_S_conv<_Tp>(_S_get()))>
2857 template<typename _Tp>
2862 using type = decltype(_S_test<_Ret>(1));
2864 #pragma GCC diagnostic pop
2866 template<typename _Fn, typename... _ArgTypes>
2867 struct __is_invocable
2868 : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2871 template<typename _Fn, typename _Tp, typename... _Args>
2872 constexpr bool __call_is_nt(__invoke_memfun_ref)
2874 using _Up = typename __inv_unwrap<_Tp>::type;
2875 return noexcept((std::declval<_Up>().*std::declval<_Fn>())(
2876 std::declval<_Args>()...));
2879 template<typename _Fn, typename _Tp, typename... _Args>
2880 constexpr bool __call_is_nt(__invoke_memfun_deref)
2882 return noexcept(((*std::declval<_Tp>()).*std::declval<_Fn>())(
2883 std::declval<_Args>()...));
2886 template<typename _Fn, typename _Tp>
2887 constexpr bool __call_is_nt(__invoke_memobj_ref)
2889 using _Up = typename __inv_unwrap<_Tp>::type;
2890 return noexcept(std::declval<_Up>().*std::declval<_Fn>());
2893 template<typename _Fn, typename _Tp>
2894 constexpr bool __call_is_nt(__invoke_memobj_deref)
2896 return noexcept((*std::declval<_Tp>()).*std::declval<_Fn>());
2899 template<typename _Fn, typename... _Args>
2900 constexpr bool __call_is_nt(__invoke_other)
2902 return noexcept(std::declval<_Fn>()(std::declval<_Args>()...));
2905 template<typename _Result, typename _Fn, typename... _Args>
2906 struct __call_is_nothrow
2908 std::__call_is_nt<_Fn, _Args...>(typename _Result::__invoke_type{})
2912 template<typename _Fn, typename... _Args>
2913 using __call_is_nothrow_
2914 = __call_is_nothrow<__invoke_result<_Fn, _Args...>, _Fn, _Args...>;
2916 // __is_nothrow_invocable (std::is_nothrow_invocable for C++11)
2917 template<typename _Fn, typename... _Args>
2918 struct __is_nothrow_invocable
2919 : __and_<__is_invocable<_Fn, _Args...>,
2920 __call_is_nothrow_<_Fn, _Args...>>::type
2923 #pragma GCC diagnostic push
2924 #pragma GCC diagnostic ignored "-Wctor-dtor-privacy"
2925 struct __nonesuchbase {};
2926 struct __nonesuch : private __nonesuchbase {
2927 ~__nonesuch() = delete;
2928 __nonesuch(__nonesuch const&) = delete;
2929 void operator=(__nonesuch const&) = delete;
2931 #pragma GCC diagnostic pop
2933 #if __cplusplus >= 201703L
2934 # define __cpp_lib_is_invocable 201703
2936 /// std::invoke_result
2937 template<typename _Functor, typename... _ArgTypes>
2938 struct invoke_result
2939 : public __invoke_result<_Functor, _ArgTypes...>
2942 /// std::invoke_result_t
2943 template<typename _Fn, typename... _Args>
2944 using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
2946 /// std::is_invocable
2947 template<typename _Fn, typename... _ArgTypes>
2949 : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>::type
2951 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
2952 "_Fn must be a complete class or an unbounded array");
2955 /// std::is_invocable_r
2956 template<typename _Ret, typename _Fn, typename... _ArgTypes>
2957 struct is_invocable_r
2958 : __is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>::type
2960 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
2961 "_Fn must be a complete class or an unbounded array");
2964 /// std::is_nothrow_invocable
2965 template<typename _Fn, typename... _ArgTypes>
2966 struct is_nothrow_invocable
2967 : __and_<__is_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, void>,
2968 __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2970 static_assert(std::__is_complete_or_unbounded(__type_identity<_Fn>{}),
2971 "_Fn must be a complete class or an unbounded array");
2974 template<typename _Result, typename _Ret, typename = void>
2975 struct __is_nt_invocable_impl : false_type { };
2977 template<typename _Result, typename _Ret>
2978 struct __is_nt_invocable_impl<_Result, _Ret,
2979 __void_t<typename _Result::type>>
2980 : __or_<is_void<_Ret>,
2981 __is_nothrow_convertible<typename _Result::type, _Ret>>
2984 /// std::is_nothrow_invocable_r
2985 template<typename _Ret, typename _Fn, typename... _ArgTypes>
2986 struct is_nothrow_invocable_r
2987 : __and_<__is_nt_invocable_impl<__invoke_result<_Fn, _ArgTypes...>, _Ret>,
2988 __call_is_nothrow_<_Fn, _ArgTypes...>>::type
2991 /// std::is_invocable_v
2992 template<typename _Fn, typename... _Args>
2993 inline constexpr bool is_invocable_v = is_invocable<_Fn, _Args...>::value;
2995 /// std::is_nothrow_invocable_v
2996 template<typename _Fn, typename... _Args>
2997 inline constexpr bool is_nothrow_invocable_v
2998 = is_nothrow_invocable<_Fn, _Args...>::value;
3000 /// std::is_invocable_r_v
3001 template<typename _Ret, typename _Fn, typename... _Args>
3002 inline constexpr bool is_invocable_r_v
3003 = is_invocable_r<_Ret, _Fn, _Args...>::value;
3005 /// std::is_nothrow_invocable_r_v
3006 template<typename _Ret, typename _Fn, typename... _Args>
3007 inline constexpr bool is_nothrow_invocable_r_v
3008 = is_nothrow_invocable_r<_Ret, _Fn, _Args...>::value;
3011 #if __cplusplus >= 201703L
3012 # define __cpp_lib_type_trait_variable_templates 201510L
3013 template <typename _Tp>
3014 inline constexpr bool is_void_v = is_void<_Tp>::value;
3015 template <typename _Tp>
3016 inline constexpr bool is_null_pointer_v = is_null_pointer<_Tp>::value;
3017 template <typename _Tp>
3018 inline constexpr bool is_integral_v = is_integral<_Tp>::value;
3019 template <typename _Tp>
3020 inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
3021 template <typename _Tp>
3022 inline constexpr bool is_array_v = is_array<_Tp>::value;
3023 template <typename _Tp>
3024 inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;
3025 template <typename _Tp>
3026 inline constexpr bool is_lvalue_reference_v =
3027 is_lvalue_reference<_Tp>::value;
3028 template <typename _Tp>
3029 inline constexpr bool is_rvalue_reference_v =
3030 is_rvalue_reference<_Tp>::value;
3031 template <typename _Tp>
3032 inline constexpr bool is_member_object_pointer_v =
3033 is_member_object_pointer<_Tp>::value;
3034 template <typename _Tp>
3035 inline constexpr bool is_member_function_pointer_v =
3036 is_member_function_pointer<_Tp>::value;
3037 template <typename _Tp>
3038 inline constexpr bool is_enum_v = is_enum<_Tp>::value;
3039 template <typename _Tp>
3040 inline constexpr bool is_union_v = is_union<_Tp>::value;
3041 template <typename _Tp>
3042 inline constexpr bool is_class_v = is_class<_Tp>::value;
3043 template <typename _Tp>
3044 inline constexpr bool is_function_v = is_function<_Tp>::value;
3045 template <typename _Tp>
3046 inline constexpr bool is_reference_v = is_reference<_Tp>::value;
3047 template <typename _Tp>
3048 inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
3049 template <typename _Tp>
3050 inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
3051 template <typename _Tp>
3052 inline constexpr bool is_object_v = is_object<_Tp>::value;
3053 template <typename _Tp>
3054 inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
3055 template <typename _Tp>
3056 inline constexpr bool is_compound_v = is_compound<_Tp>::value;
3057 template <typename _Tp>
3058 inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value;
3059 template <typename _Tp>
3060 inline constexpr bool is_const_v = is_const<_Tp>::value;
3061 template <typename _Tp>
3062 inline constexpr bool is_volatile_v = is_volatile<_Tp>::value;
3063 template <typename _Tp>
3064 inline constexpr bool is_trivial_v = is_trivial<_Tp>::value;
3065 template <typename _Tp>
3066 inline constexpr bool is_trivially_copyable_v =
3067 is_trivially_copyable<_Tp>::value;
3068 template <typename _Tp>
3069 inline constexpr bool is_standard_layout_v = is_standard_layout<_Tp>::value;
3070 #pragma GCC diagnostic push
3071 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
3072 template <typename _Tp>
3073 _GLIBCXX20_DEPRECATED("use is_standard_layout_v && is_trivial_v instead")
3074 inline constexpr bool is_pod_v = is_pod<_Tp>::value;
3075 #pragma GCC diagnostic pop
3076 template <typename _Tp>
3077 inline constexpr bool is_literal_type_v = is_literal_type<_Tp>::value;
3078 template <typename _Tp>
3079 inline constexpr bool is_empty_v = is_empty<_Tp>::value;
3080 template <typename _Tp>
3081 inline constexpr bool is_polymorphic_v = is_polymorphic<_Tp>::value;
3082 template <typename _Tp>
3083 inline constexpr bool is_abstract_v = is_abstract<_Tp>::value;
3084 template <typename _Tp>
3085 inline constexpr bool is_final_v = is_final<_Tp>::value;
3086 template <typename _Tp>
3087 inline constexpr bool is_signed_v = is_signed<_Tp>::value;
3088 template <typename _Tp>
3089 inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
3090 template <typename _Tp, typename... _Args>
3091 inline constexpr bool is_constructible_v =
3092 is_constructible<_Tp, _Args...>::value;
3093 template <typename _Tp>
3094 inline constexpr bool is_default_constructible_v =
3095 is_default_constructible<_Tp>::value;
3096 template <typename _Tp>
3097 inline constexpr bool is_copy_constructible_v =
3098 is_copy_constructible<_Tp>::value;
3099 template <typename _Tp>
3100 inline constexpr bool is_move_constructible_v =
3101 is_move_constructible<_Tp>::value;
3102 template <typename _Tp, typename _Up>
3103 inline constexpr bool is_assignable_v = is_assignable<_Tp, _Up>::value;
3104 template <typename _Tp>
3105 inline constexpr bool is_copy_assignable_v = is_copy_assignable<_Tp>::value;
3106 template <typename _Tp>
3107 inline constexpr bool is_move_assignable_v = is_move_assignable<_Tp>::value;
3108 template <typename _Tp>
3109 inline constexpr bool is_destructible_v = is_destructible<_Tp>::value;
3110 template <typename _Tp, typename... _Args>
3111 inline constexpr bool is_trivially_constructible_v =
3112 is_trivially_constructible<_Tp, _Args...>::value;
3113 template <typename _Tp>
3114 inline constexpr bool is_trivially_default_constructible_v =
3115 is_trivially_default_constructible<_Tp>::value;
3116 template <typename _Tp>
3117 inline constexpr bool is_trivially_copy_constructible_v =
3118 is_trivially_copy_constructible<_Tp>::value;
3119 template <typename _Tp>
3120 inline constexpr bool is_trivially_move_constructible_v =
3121 is_trivially_move_constructible<_Tp>::value;
3122 template <typename _Tp, typename _Up>
3123 inline constexpr bool is_trivially_assignable_v =
3124 is_trivially_assignable<_Tp, _Up>::value;
3125 template <typename _Tp>
3126 inline constexpr bool is_trivially_copy_assignable_v =
3127 is_trivially_copy_assignable<_Tp>::value;
3128 template <typename _Tp>
3129 inline constexpr bool is_trivially_move_assignable_v =
3130 is_trivially_move_assignable<_Tp>::value;
3131 template <typename _Tp>
3132 inline constexpr bool is_trivially_destructible_v =
3133 is_trivially_destructible<_Tp>::value;
3134 template <typename _Tp, typename... _Args>
3135 inline constexpr bool is_nothrow_constructible_v =
3136 is_nothrow_constructible<_Tp, _Args...>::value;
3137 template <typename _Tp>
3138 inline constexpr bool is_nothrow_default_constructible_v =
3139 is_nothrow_default_constructible<_Tp>::value;
3140 template <typename _Tp>
3141 inline constexpr bool is_nothrow_copy_constructible_v =
3142 is_nothrow_copy_constructible<_Tp>::value;
3143 template <typename _Tp>
3144 inline constexpr bool is_nothrow_move_constructible_v =
3145 is_nothrow_move_constructible<_Tp>::value;
3146 template <typename _Tp, typename _Up>
3147 inline constexpr bool is_nothrow_assignable_v =
3148 is_nothrow_assignable<_Tp, _Up>::value;
3149 template <typename _Tp>
3150 inline constexpr bool is_nothrow_copy_assignable_v =
3151 is_nothrow_copy_assignable<_Tp>::value;
3152 template <typename _Tp>
3153 inline constexpr bool is_nothrow_move_assignable_v =
3154 is_nothrow_move_assignable<_Tp>::value;
3155 template <typename _Tp>
3156 inline constexpr bool is_nothrow_destructible_v =
3157 is_nothrow_destructible<_Tp>::value;
3158 template <typename _Tp>
3159 inline constexpr bool has_virtual_destructor_v =
3160 has_virtual_destructor<_Tp>::value;
3161 template <typename _Tp>
3162 inline constexpr size_t alignment_of_v = alignment_of<_Tp>::value;
3163 template <typename _Tp>
3164 inline constexpr size_t rank_v = rank<_Tp>::value;
3165 template <typename _Tp, unsigned _Idx = 0>
3166 inline constexpr size_t extent_v = extent<_Tp, _Idx>::value;
3167 #ifdef _GLIBCXX_BUILTIN_IS_SAME_AS
3168 template <typename _Tp, typename _Up>
3169 inline constexpr bool is_same_v = _GLIBCXX_BUILTIN_IS_SAME_AS(_Tp, _Up);
3171 template <typename _Tp, typename _Up>
3172 inline constexpr bool is_same_v = std::is_same<_Tp, _Up>::value;
3174 template <typename _Base, typename _Derived>
3175 inline constexpr bool is_base_of_v = is_base_of<_Base, _Derived>::value;
3176 template <typename _From, typename _To>
3177 inline constexpr bool is_convertible_v = is_convertible<_From, _To>::value;
3179 #ifdef _GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP
3180 # define __cpp_lib_has_unique_object_representations 201606
3181 /// has_unique_object_representations
3182 template<typename _Tp>
3183 struct has_unique_object_representations
3184 : bool_constant<__has_unique_object_representations(
3185 remove_cv_t<remove_all_extents_t<_Tp>>
3188 static_assert(std::__is_complete_or_unbounded(__type_identity<_Tp>{}),
3189 "template argument must be a complete class or an unbounded array");
3192 template<typename _Tp>
3193 inline constexpr bool has_unique_object_representations_v
3194 = has_unique_object_representations<_Tp>::value;
3197 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE
3198 # define __cpp_lib_is_aggregate 201703
3200 template<typename _Tp>
3202 : bool_constant<__is_aggregate(remove_cv_t<_Tp>)>
3206 template<typename _Tp>
3207 inline constexpr bool is_aggregate_v = is_aggregate<_Tp>::value;
3211 #if __cplusplus > 201703L
3212 /// Remove references and cv-qualifiers.
3213 template<typename _Tp>
3216 using type = __remove_cvref_t<_Tp>;
3219 template<typename _Tp>
3220 using remove_cvref_t = __remove_cvref_t<_Tp>;
3222 /// Identity metafunction.
3223 template<typename _Tp>
3224 struct type_identity { using type = _Tp; };
3226 template<typename _Tp>
3227 using type_identity_t = typename type_identity<_Tp>::type;
3229 #define __cpp_lib_unwrap_ref 201811L
3231 /// Unwrap a reference_wrapper
3232 template<typename _Tp>
3233 struct unwrap_reference { using type = _Tp; };
3235 template<typename _Tp>
3236 struct unwrap_reference<reference_wrapper<_Tp>> { using type = _Tp&; };
3238 template<typename _Tp>
3239 using unwrap_reference_t = typename unwrap_reference<_Tp>::type;
3241 /// Decay type and if it's a reference_wrapper, unwrap it
3242 template<typename _Tp>
3243 struct unwrap_ref_decay { using type = unwrap_reference_t<decay_t<_Tp>>; };
3245 template<typename _Tp>
3246 using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
3248 #define __cpp_lib_bounded_array_traits 201902L
3250 /// True for a type that is an array of known bound.
3251 template<typename _Tp>
3252 struct is_bounded_array
3253 : public __is_array_known_bounds<_Tp>
3256 /// True for a type that is an array of unknown bound.
3257 template<typename _Tp>
3258 struct is_unbounded_array
3259 : public __is_array_unknown_bounds<_Tp>
3262 template<typename _Tp>
3263 inline constexpr bool is_bounded_array_v
3264 = is_bounded_array<_Tp>::value;
3266 template<typename _Tp>
3267 inline constexpr bool is_unbounded_array_v
3268 = is_unbounded_array<_Tp>::value;
3270 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
3272 #define __cpp_lib_is_constant_evaluated 201811L
3274 constexpr inline bool
3275 is_constant_evaluated() noexcept
3276 { return __builtin_is_constant_evaluated(); }
3279 template<typename _From, typename _To>
3280 using __copy_cv = typename __match_cv_qualifiers<_From, _To>::__type;
3282 template<typename _Xp, typename _Yp>
3284 = decltype(false ? declval<_Xp(&)()>()() : declval<_Yp(&)()>()());
3286 template<typename _Ap, typename _Bp, typename = void>
3287 struct __common_ref_impl
3290 // [meta.trans.other], COMMON-REF(A, B)
3291 template<typename _Ap, typename _Bp>
3292 using __common_ref = typename __common_ref_impl<_Ap, _Bp>::type;
3294 // If A and B are both lvalue reference types, ...
3295 template<typename _Xp, typename _Yp>
3296 struct __common_ref_impl<_Xp&, _Yp&,
3297 __void_t<__cond_res<__copy_cv<_Xp, _Yp>&, __copy_cv<_Yp, _Xp>&>>>
3298 { using type = __cond_res<__copy_cv<_Xp, _Yp>&, __copy_cv<_Yp, _Xp>&>; };
3300 // let C be remove_reference_t<COMMON-REF(X&, Y&)>&&
3301 template<typename _Xp, typename _Yp>
3302 using __common_ref_C = remove_reference_t<__common_ref<_Xp&, _Yp&>>&&;
3304 // If A and B are both rvalue reference types, ...
3305 template<typename _Xp, typename _Yp>
3306 struct __common_ref_impl<_Xp&&, _Yp&&,
3307 _Require<is_convertible<_Xp&&, __common_ref_C<_Xp, _Yp>>,
3308 is_convertible<_Yp&&, __common_ref_C<_Xp, _Yp>>>>
3309 { using type = __common_ref_C<_Xp, _Yp>; };
3311 // let D be COMMON-REF(const X&, Y&)
3312 template<typename _Xp, typename _Yp>
3313 using __common_ref_D = __common_ref<const _Xp&, _Yp&>;
3315 // If A is an rvalue reference and B is an lvalue reference, ...
3316 template<typename _Xp, typename _Yp>
3317 struct __common_ref_impl<_Xp&&, _Yp&,
3318 _Require<is_convertible<_Xp&&, __common_ref_D<_Xp, _Yp>>>>
3319 { using type = __common_ref_D<_Xp, _Yp>; };
3321 // If A is an lvalue reference and B is an rvalue reference, ...
3322 template<typename _Xp, typename _Yp>
3323 struct __common_ref_impl<_Xp&, _Yp&&>
3324 : __common_ref_impl<_Yp&&, _Xp&>
3327 template<typename _Tp, typename _Up,
3328 template<typename> class _TQual, template<typename> class _UQual>
3329 struct basic_common_reference
3332 template<typename _Tp>
3334 { template<typename _Up> using __type = __copy_cv<_Tp, _Up>; };
3336 template<typename _Tp>
3338 { template<typename _Up> using __type = __copy_cv<_Tp, _Up>&; };
3340 template<typename _Tp>
3341 struct __xref<_Tp&&>
3342 { template<typename _Up> using __type = __copy_cv<_Tp, _Up>&&; };
3344 template<typename _Tp1, typename _Tp2>
3345 using __basic_common_ref
3346 = typename basic_common_reference<remove_cvref_t<_Tp1>,
3347 remove_cvref_t<_Tp2>,
3348 __xref<_Tp1>::template __type,
3349 __xref<_Tp2>::template __type>::type;
3351 template<typename... _Tp>
3352 struct common_reference;
3354 template<typename... _Tp>
3355 using common_reference_t = typename common_reference<_Tp...>::type;
3357 // If sizeof...(T) is zero, there shall be no member type.
3359 struct common_reference<>
3362 // If sizeof...(T) is one ...
3363 template<typename _Tp0>
3364 struct common_reference<_Tp0>
3365 { using type = _Tp0; };
3367 template<typename _Tp1, typename _Tp2, int _Bullet = 1, typename = void>
3368 struct __common_reference_impl
3369 : __common_reference_impl<_Tp1, _Tp2, _Bullet + 1>
3372 // If sizeof...(T) is two ...
3373 template<typename _Tp1, typename _Tp2>
3374 struct common_reference<_Tp1, _Tp2>
3375 : __common_reference_impl<_Tp1, _Tp2>
3378 // If T1 and T2 are reference types and COMMON-REF(T1, T2) is well-formed, ...
3379 template<typename _Tp1, typename _Tp2>
3380 struct __common_reference_impl<_Tp1&, _Tp2&, 1,
3381 void_t<__common_ref<_Tp1&, _Tp2&>>>
3382 { using type = __common_ref<_Tp1&, _Tp2&>; };
3384 template<typename _Tp1, typename _Tp2>
3385 struct __common_reference_impl<_Tp1&&, _Tp2&&, 1,
3386 void_t<__common_ref<_Tp1&&, _Tp2&&>>>
3387 { using type = __common_ref<_Tp1&&, _Tp2&&>; };
3389 template<typename _Tp1, typename _Tp2>
3390 struct __common_reference_impl<_Tp1&, _Tp2&&, 1,
3391 void_t<__common_ref<_Tp1&, _Tp2&&>>>
3392 { using type = __common_ref<_Tp1&, _Tp2&&>; };
3394 template<typename _Tp1, typename _Tp2>
3395 struct __common_reference_impl<_Tp1&&, _Tp2&, 1,
3396 void_t<__common_ref<_Tp1&&, _Tp2&>>>
3397 { using type = __common_ref<_Tp1&&, _Tp2&>; };
3399 // Otherwise, if basic_common_reference<...>::type is well-formed, ...
3400 template<typename _Tp1, typename _Tp2>
3401 struct __common_reference_impl<_Tp1, _Tp2, 2,
3402 void_t<__basic_common_ref<_Tp1, _Tp2>>>
3403 { using type = __basic_common_ref<_Tp1, _Tp2>; };
3405 // Otherwise, if COND-RES(T1, T2) is well-formed, ...
3406 template<typename _Tp1, typename _Tp2>
3407 struct __common_reference_impl<_Tp1, _Tp2, 3,
3408 void_t<__cond_res<_Tp1, _Tp2>>>
3409 { using type = __cond_res<_Tp1, _Tp2>; };
3411 // Otherwise, if common_type_t<T1, T2> is well-formed, ...
3412 template<typename _Tp1, typename _Tp2>
3413 struct __common_reference_impl<_Tp1, _Tp2, 4,
3414 void_t<common_type_t<_Tp1, _Tp2>>>
3415 { using type = common_type_t<_Tp1, _Tp2>; };
3417 // Otherwise, there shall be no member type.
3418 template<typename _Tp1, typename _Tp2>
3419 struct __common_reference_impl<_Tp1, _Tp2, 5, void>
3422 // Otherwise, if sizeof...(T) is greater than two, ...
3423 template<typename _Tp1, typename _Tp2, typename... _Rest>
3424 struct common_reference<_Tp1, _Tp2, _Rest...>
3425 : __common_type_fold<common_reference<_Tp1, _Tp2>,
3426 __common_type_pack<_Rest...>>
3429 // Reuse __common_type_fold for common_reference<T1, T2, Rest...>
3430 template<typename _Tp1, typename _Tp2, typename... _Rest>
3431 struct __common_type_fold<common_reference<_Tp1, _Tp2>,
3432 __common_type_pack<_Rest...>,
3433 void_t<common_reference_t<_Tp1, _Tp2>>>
3434 : public common_reference<common_reference_t<_Tp1, _Tp2>, _Rest...>
3439 _GLIBCXX_END_NAMESPACE_VERSION
3444 #endif // _GLIBCXX_TYPE_TRAITS