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// This header is unguarded on purpose. This header is an implementation detail of function_ref.h
10// and generates multiple versions of std::function_ref
11
12#include <__assert>
13#include <__config>
14#include <__functional/function_ref_common.h>
15#include <__functional/invoke.h>
16#include <__memory/addressof.h>
17#include <__type_traits/conditional.h>
18#include <__type_traits/conjunction.h>
19#include <__type_traits/invoke.h>
20#include <__type_traits/is_const.h>
21#include <__type_traits/is_convertible.h>
22#include <__type_traits/is_function.h>
23#include <__type_traits/is_member_pointer.h>
24#include <__type_traits/is_object.h>
25#include <__type_traits/is_pointer.h>
26#include <__type_traits/is_reference.h>
27#include <__type_traits/is_same.h>
28#include <__type_traits/is_void.h>
29#include <__type_traits/register_passable.h>
30#include <__type_traits/remove_cv.h>
31#include <__type_traits/remove_cvref.h>
32#include <__type_traits/remove_pointer.h>
33#include <__type_traits/remove_reference.h>
34#include <__utility/constant_wrapper.h>
35#include <__utility/forward.h>
36
37#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
38# pragma GCC system_header
39#endif
40
41#ifndef _LIBCPP___FUNCTIONAL_FUNCTION_REF_H
42# error This header should only be included from function_ref.h
43#endif
44
45_LIBCPP_BEGIN_NAMESPACE_STD
46
47#if _LIBCPP_STD_VER >= 26
48
49template <class...>
50class function_ref;
51
52template <bool _NoExcept1, bool _NoExcept2, class _Rp, class... _ArgTypes>
53struct __is_convertible_from_specialization<
54 function_ref<_Rp(_ArgTypes...) _LIBCPP_FUNCTION_REF_CV noexcept(_NoExcept1)>,
55 function_ref<_Rp(_ArgTypes...) const noexcept(_NoExcept2)> >
56 : is_convertible<_Rp (&)(_ArgTypes...) noexcept(_NoExcept2), _Rp (&)(_ArgTypes...) noexcept(_NoExcept1)> {};
57
58template <bool _NoExcept1, bool _NoExcept2, class _Rp, class... _ArgTypes>
59struct __is_convertible_from_specialization<
60 function_ref<_Rp(_ArgTypes...) _LIBCPP_FUNCTION_REF_CV noexcept(_NoExcept1)>,
61 function_ref<_Rp(_ArgTypes...) noexcept(_NoExcept2)> >
62 : _And<is_convertible<_Rp (&)(_ArgTypes...) noexcept(_NoExcept2), _Rp (&)(_ArgTypes...) noexcept(_NoExcept1)>,
63 is_convertible<_LIBCPP_FUNCTION_REF_CV int&, int&>> {};
64
65template <class _Rp, class... _ArgTypes, bool __is_noexcept>
66class function_ref<_Rp(_ArgTypes...) _LIBCPP_FUNCTION_REF_CV noexcept(__is_noexcept)> {
67private:
68 template <class... _Tp>
69 static constexpr bool __is_invocable_using =
70 _If<__is_noexcept, is_nothrow_invocable_r<_Rp, _Tp..., _ArgTypes...>, is_invocable_r<_Rp, _Tp..., _ArgTypes...>>::
71 value;
72
73 template <class _Fn2>
74 static constexpr bool __is_convertible_from_specialization_v =
75 __is_convertible_from_specialization<function_ref, _Fn2>::value;
76
77 template <class... _Tp>
78 friend class function_ref;
79
80 template <class _Arg>
81 using __arg_t _LIBCPP_NODEBUG = _If<__register_passable<_Arg>, _Arg, _Arg&&>;
82
83 using __storage_t _LIBCPP_NODEBUG = __function_ref_storage;
84
85 using __call_t _LIBCPP_NODEBUG = _Rp (*)(__storage_t, __arg_t<_ArgTypes>...) noexcept(__is_noexcept);
86
87 __storage_t __storage_;
88 __call_t __call_;
89
90public:
91 template <class _Fp>
92 requires is_function_v<_Fp> && __is_invocable_using<_Fp>
93 _LIBCPP_HIDE_FROM_ABI function_ref(_Fp* __fn_ptr) noexcept
94 : __storage_(__fn_ptr),
95 __call_([](__storage_t __storage, __arg_t<_ArgTypes>... __args) static noexcept(__is_noexcept) -> _Rp {
96 _Fp* __fn_ptr1 = __storage_t::template __get<_Fp>(__storage);
97 return std::invoke_r<_Rp>(__fn_ptr1, std::forward<__arg_t<_ArgTypes>>(__args)...);
98 }) {
99 _LIBCPP_ASSERT_NON_NULL(__fn_ptr != nullptr, "the function pointer should not be a nullptr");
100 }
101
102 template <class _Fn, class _Tp = remove_reference_t<_Fn>>
103 requires(!is_same_v<remove_cvref_t<_Fn>, function_ref> && !is_member_pointer_v<_Tp> &&
104 __is_invocable_using<_LIBCPP_FUNCTION_REF_CV _Tp&> && !__is_convertible_from_specialization_v<_Tp>)
105 _LIBCPP_HIDE_FROM_ABI constexpr function_ref(_Fn&& __obj) noexcept {
106 using _Dn = remove_cv_t<_Tp>;
107 if constexpr (__statically_callable<_Dn, __arg_t<_ArgTypes>...>) {
108 __call_ = [](__storage_t, __arg_t<_ArgTypes>... __args) static noexcept(__is_noexcept) -> _Rp {
109 return _Dn::operator()(std::forward<__arg_t<_ArgTypes>>(__args)...);
110 };
111 } else {
112 __storage_ = __storage_t(std::addressof(__obj)),
113 __call_ = [](__storage_t __storage, __arg_t<_ArgTypes>... __args) static noexcept(__is_noexcept) -> _Rp {
114 _LIBCPP_FUNCTION_REF_CV _Tp& __obj1 = *__storage_t::template __get<_Tp>(__storage);
115 return std::invoke_r<_Rp>(__obj1, std::forward<__arg_t<_ArgTypes>>(__args)...);
116 };
117 }
118 }
119
120 template <class _Fn, class _Tp = remove_reference_t<_Fn>>
121 requires(!is_same_v<remove_cvref_t<_Fn>, function_ref> && !is_member_pointer_v<_Tp> &&
122 __is_invocable_using<_LIBCPP_FUNCTION_REF_CV _Tp&> && __is_convertible_from_specialization_v<_Tp>)
123 _LIBCPP_HIDE_FROM_ABI constexpr function_ref(_Fn&& __obj) noexcept
124 : __storage_(__obj.__storage_), __call_(__obj.__call_) {}
125
126 template <auto _Cw, class _Fn>
127 requires __is_invocable_using<const _Fn&>
128 _LIBCPP_HIDE_FROM_ABI constexpr function_ref(constant_wrapper<_Cw, _Fn> __f) noexcept
129 : __call_([](__storage_t, __arg_t<_ArgTypes>... __args) static noexcept(__is_noexcept) -> _Rp {
130 return std::invoke_r<_Rp>(decltype(__f)::value, std::forward<__arg_t<_ArgTypes>>(__args)...);
131 }) {
132 if constexpr (is_pointer_v<_Fn> || is_member_pointer_v<_Fn>) {
133 static_assert(__f.value != nullptr, "the function pointer should not be a nullptr");
134 }
135 if constexpr (sizeof...(_ArgTypes) > 0 && (__constexpr_param<remove_cvref_t<_ArgTypes>> && ...)) {
136 static_assert(
137 !requires {
138 typename constant_wrapper<std::invoke(decltype(__f)::value, remove_cvref_t<_ArgTypes>::value...)>;
139 },
140 "cw(args...) should be equivalent to fn(args...), otherwise the intended behavior for a function_ref "
141 "constructed from cw would be ambiguous");
142 }
143 }
144
145 template <auto _Cw, class _Fn, class _Up, class _Tp = remove_reference_t<_Up>>
146 requires(!is_rvalue_reference_v<_Up &&>) && __is_invocable_using<const _Fn&, _LIBCPP_FUNCTION_REF_CV _Tp&>
147 _LIBCPP_HIDE_FROM_ABI constexpr function_ref(constant_wrapper<_Cw, _Fn> __f, _Up&& __obj) noexcept
148 : __storage_(std::addressof(__obj)),
149 __call_([](__storage_t __storage, __arg_t<_ArgTypes>... __args) static noexcept(__is_noexcept) -> _Rp {
150 auto& __obj1 = static_cast<_LIBCPP_FUNCTION_REF_CV _Tp&>(*__storage_t::template __get<_Tp>(__storage));
151 return std::invoke_r<_Rp>(decltype(__f)::value, __obj1, std::forward<__arg_t<_ArgTypes>>(__args)...);
152 }) {
153 if constexpr (is_pointer_v<_Fn> || is_member_pointer_v<_Fn>) {
154 static_assert(__f.value != nullptr, "the function pointer should not be a nullptr");
155 }
156 }
157
158 template <auto _Cw, class _Fn, class _Tp>
159 requires __is_invocable_using<const _Fn&, _LIBCPP_FUNCTION_REF_CV _Tp*>
160 _LIBCPP_HIDE_FROM_ABI constexpr function_ref(constant_wrapper<_Cw, _Fn> __f,
161 _LIBCPP_FUNCTION_REF_CV _Tp* __obj_ptr) noexcept
162 : __storage_(__obj_ptr),
163 __call_([](__storage_t __storage, __arg_t<_ArgTypes>... __args) static noexcept(__is_noexcept) -> _Rp {
164 auto* __obj = __storage_t::template __get<_LIBCPP_FUNCTION_REF_CV _Tp>(__storage);
165 return std::invoke_r<_Rp>(decltype(__f)::value, __obj, std::forward<__arg_t<_ArgTypes>>(__args)...);
166 }) {
167 if constexpr (is_pointer_v<_Fn> || is_member_pointer_v<_Fn>) {
168 static_assert(__f.value != nullptr, "the function pointer should not be a nullptr");
169 }
170
171 if constexpr (is_member_pointer_v<_Fn>) {
172 _LIBCPP_ASSERT_NON_NULL(__obj_ptr != nullptr, "the object pointer should not be a nullptr");
173 }
174 }
175
176 _LIBCPP_HIDE_FROM_ABI constexpr function_ref(const function_ref&) noexcept = default;
177
178 _LIBCPP_HIDE_FROM_ABI constexpr function_ref& operator=(const function_ref&) noexcept = default;
179
180 template <class _Tp>
181 requires(!__is_convertible_from_specialization_v<_Tp>) && (!is_pointer_v<_Tp>) && (!__is_constant_wrapper<_Tp>)
182 _LIBCPP_HIDE_FROM_ABI function_ref& operator=(_Tp) = delete;
183
184 _LIBCPP_HIDE_FROM_ABI _Rp operator()(_ArgTypes... __args) const noexcept(__is_noexcept) {
185 return __call_(__storage_, std::forward<_ArgTypes>(__args)...);
186 }
187};
188
189template <class _Tp, class _Rp, class _Gp, class... _ArgTypes, bool __is_noexcept>
190struct __function_ref_bind<_Rp (_Gp::*)(_ArgTypes...) _LIBCPP_FUNCTION_REF_CV noexcept(__is_noexcept), _Tp> {
191 using type _LIBCPP_NODEBUG = _Rp(_ArgTypes...) noexcept(__is_noexcept);
192};
193
194template <class _Tp, class _Rp, class _Gp, class... _ArgTypes, bool __is_noexcept>
195struct __function_ref_bind<_Rp (_Gp::*)(_ArgTypes...) _LIBCPP_FUNCTION_REF_CV & noexcept(__is_noexcept), _Tp> {
196 using type _LIBCPP_NODEBUG = _Rp(_ArgTypes...) noexcept(__is_noexcept);
197};
198
199#endif // _LIBCPP_STD_VER >= 26
200
201_LIBCPP_END_NAMESPACE_STD
202