| 1 | //===----------------------------------------------------------------------===// |
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #ifndef _LIBCPP___TUPLE_SFINAE_HELPERS_H |
| 10 | #define _LIBCPP___TUPLE_SFINAE_HELPERS_H |
| 11 | |
| 12 | #include <__config> |
| 13 | #include <__cstddef/size_t.h> |
| 14 | #include <__fwd/tuple.h> |
| 15 | #include <__tuple/make_tuple_types.h> |
| 16 | #include <__tuple/tuple_element.h> |
| 17 | #include <__tuple/tuple_like_ext.h> |
| 18 | #include <__tuple/tuple_size.h> |
| 19 | #include <__tuple/tuple_types.h> |
| 20 | #include <__type_traits/conjunction.h> |
| 21 | #include <__type_traits/enable_if.h> |
| 22 | #include <__type_traits/integral_constant.h> |
| 23 | #include <__type_traits/is_constructible.h> |
| 24 | #include <__type_traits/is_same.h> |
| 25 | #include <__type_traits/remove_cvref.h> |
| 26 | #include <__type_traits/remove_reference.h> |
| 27 | |
| 28 | #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| 29 | # pragma GCC system_header |
| 30 | #endif |
| 31 | |
| 32 | _LIBCPP_BEGIN_NAMESPACE_STD |
| 33 | |
| 34 | #ifndef _LIBCPP_CXX03_LANG |
| 35 | |
| 36 | struct __tuple_sfinae_base { |
| 37 | template <template <class, class...> class _Trait, class... _LArgs, class... _RArgs> |
| 38 | static auto __do_test(__tuple_types<_LArgs...>, |
| 39 | __tuple_types<_RArgs...>) -> __all<__enable_if_t<_Trait<_LArgs, _RArgs>::value, bool>{true}...>; |
| 40 | template <template <class...> class> |
| 41 | static auto __do_test(...) -> false_type; |
| 42 | |
| 43 | template <class _FromArgs, class _ToArgs> |
| 44 | using __constructible _LIBCPP_NODEBUG = decltype(__do_test<is_constructible>(_ToArgs{}, _FromArgs{})); |
| 45 | }; |
| 46 | |
| 47 | // __tuple_constructible |
| 48 | |
| 49 | template <class _Tp, |
| 50 | class _Up, |
| 51 | bool = __tuple_like_ext<__libcpp_remove_reference_t<_Tp> >::value, |
| 52 | bool = __tuple_like_ext<_Up>::value> |
| 53 | struct __tuple_constructible : public false_type {}; |
| 54 | |
| 55 | template <class _Tp, class _Up> |
| 56 | struct __tuple_constructible<_Tp, _Up, true, true> |
| 57 | : public __tuple_sfinae_base::__constructible< typename __make_tuple_types<_Tp>::type, |
| 58 | typename __make_tuple_types<_Up>::type > {}; |
| 59 | |
| 60 | template <size_t _Ip, class... _Tp> |
| 61 | struct tuple_element<_Ip, tuple<_Tp...> > { |
| 62 | using type _LIBCPP_NODEBUG = typename tuple_element<_Ip, __tuple_types<_Tp...> >::type; |
| 63 | }; |
| 64 | |
| 65 | struct _LIBCPP_EXPORTED_FROM_ABI __check_tuple_constructor_fail { |
| 66 | static _LIBCPP_HIDE_FROM_ABI constexpr bool __enable_explicit_default() { return false; } |
| 67 | static _LIBCPP_HIDE_FROM_ABI constexpr bool __enable_implicit_default() { return false; } |
| 68 | template <class...> |
| 69 | static _LIBCPP_HIDE_FROM_ABI constexpr bool __enable_explicit() { |
| 70 | return false; |
| 71 | } |
| 72 | template <class...> |
| 73 | static _LIBCPP_HIDE_FROM_ABI constexpr bool __enable_implicit() { |
| 74 | return false; |
| 75 | } |
| 76 | template <class...> |
| 77 | static _LIBCPP_HIDE_FROM_ABI constexpr bool __enable_assign() { |
| 78 | return false; |
| 79 | } |
| 80 | }; |
| 81 | #endif // !defined(_LIBCPP_CXX03_LANG) |
| 82 | |
| 83 | #if _LIBCPP_STD_VER >= 17 |
| 84 | |
| 85 | template <bool _CanCopy, bool _CanMove> |
| 86 | struct __sfinae_ctor_base {}; |
| 87 | template <> |
| 88 | struct __sfinae_ctor_base<false, false> { |
| 89 | __sfinae_ctor_base() = default; |
| 90 | __sfinae_ctor_base(__sfinae_ctor_base const&) = delete; |
| 91 | __sfinae_ctor_base(__sfinae_ctor_base&&) = delete; |
| 92 | __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default; |
| 93 | __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default; |
| 94 | }; |
| 95 | template <> |
| 96 | struct __sfinae_ctor_base<true, false> { |
| 97 | __sfinae_ctor_base() = default; |
| 98 | __sfinae_ctor_base(__sfinae_ctor_base const&) = default; |
| 99 | __sfinae_ctor_base(__sfinae_ctor_base&&) = delete; |
| 100 | __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default; |
| 101 | __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default; |
| 102 | }; |
| 103 | template <> |
| 104 | struct __sfinae_ctor_base<false, true> { |
| 105 | __sfinae_ctor_base() = default; |
| 106 | __sfinae_ctor_base(__sfinae_ctor_base const&) = delete; |
| 107 | __sfinae_ctor_base(__sfinae_ctor_base&&) = default; |
| 108 | __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default; |
| 109 | __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default; |
| 110 | }; |
| 111 | |
| 112 | template <bool _CanCopy, bool _CanMove> |
| 113 | struct __sfinae_assign_base {}; |
| 114 | template <> |
| 115 | struct __sfinae_assign_base<false, false> { |
| 116 | __sfinae_assign_base() = default; |
| 117 | __sfinae_assign_base(__sfinae_assign_base const&) = default; |
| 118 | __sfinae_assign_base(__sfinae_assign_base&&) = default; |
| 119 | __sfinae_assign_base& operator=(__sfinae_assign_base const&) = delete; |
| 120 | __sfinae_assign_base& operator=(__sfinae_assign_base&&) = delete; |
| 121 | }; |
| 122 | template <> |
| 123 | struct __sfinae_assign_base<true, false> { |
| 124 | __sfinae_assign_base() = default; |
| 125 | __sfinae_assign_base(__sfinae_assign_base const&) = default; |
| 126 | __sfinae_assign_base(__sfinae_assign_base&&) = default; |
| 127 | __sfinae_assign_base& operator=(__sfinae_assign_base const&) = default; |
| 128 | __sfinae_assign_base& operator=(__sfinae_assign_base&&) = delete; |
| 129 | }; |
| 130 | template <> |
| 131 | struct __sfinae_assign_base<false, true> { |
| 132 | __sfinae_assign_base() = default; |
| 133 | __sfinae_assign_base(__sfinae_assign_base const&) = default; |
| 134 | __sfinae_assign_base(__sfinae_assign_base&&) = default; |
| 135 | __sfinae_assign_base& operator=(__sfinae_assign_base const&) = delete; |
| 136 | __sfinae_assign_base& operator=(__sfinae_assign_base&&) = default; |
| 137 | }; |
| 138 | #endif // _LIBCPP_STD_VER >= 17 |
| 139 | |
| 140 | _LIBCPP_END_NAMESPACE_STD |
| 141 | |
| 142 | #endif // _LIBCPP___TUPLE_SFINAE_HELPERS_H |
| 143 | |