Nikolas Klauser 1972d1e86a [libc++] Granularize even more of type_traits
Reviewed By: ldionne, #libc

Spies: libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D126593
2022-06-10 11:56:38 +02:00

775 lines
24 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___FUNCTIONAL_INVOKE_H
#define _LIBCPP___FUNCTIONAL_INVOKE_H
#include <__config>
#include <__type_traits/add_lvalue_reference.h>
#include <__type_traits/apply_cv.h>
#include <__type_traits/conditional.h>
#include <__type_traits/decay.h>
#include <__type_traits/enable_if.h>
#include <__type_traits/integral_constant.h>
#include <__type_traits/is_base_of.h>
#include <__type_traits/is_core_convertible.h>
#include <__type_traits/is_member_function_pointer.h>
#include <__type_traits/is_member_object_pointer.h>
#include <__type_traits/is_reference_wrapper.h>
#include <__type_traits/is_same.h>
#include <__type_traits/is_void.h>
#include <__type_traits/remove_cv.h>
#include <__utility/declval.h>
#include <__utility/forward.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
// TODO: Disentangle the type traits and std::invoke properly
_LIBCPP_BEGIN_NAMESPACE_STD
struct __any
{
__any(...);
};
struct __nat
{
#ifndef _LIBCPP_CXX03_LANG
__nat() = delete;
__nat(const __nat&) = delete;
__nat& operator=(const __nat&) = delete;
~__nat() = delete;
#endif
};
template <class _MP, bool _IsMemberFunctionPtr, bool _IsMemberObjectPtr>
struct __member_pointer_traits_imp
{
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...), true, false>
{
typedef _Class _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...), true, false>
{
typedef _Class _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const, true, false>
{
typedef _Class const _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const, true, false>
{
typedef _Class const _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) volatile, true, false>
{
typedef _Class volatile _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) volatile, true, false>
{
typedef _Class volatile _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const volatile, true, false>
{
typedef _Class const volatile _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const volatile, true, false>
{
typedef _Class const volatile _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
#if __has_feature(cxx_reference_qualified_functions) || defined(_LIBCPP_COMPILER_GCC)
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) &, true, false>
{
typedef _Class& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) &, true, false>
{
typedef _Class& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const&, true, false>
{
typedef _Class const& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const&, true, false>
{
typedef _Class const& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) volatile&, true, false>
{
typedef _Class volatile& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) volatile&, true, false>
{
typedef _Class volatile& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const volatile&, true, false>
{
typedef _Class const volatile& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const volatile&, true, false>
{
typedef _Class const volatile& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) &&, true, false>
{
typedef _Class&& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) &&, true, false>
{
typedef _Class&& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const&&, true, false>
{
typedef _Class const&& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const&&, true, false>
{
typedef _Class const&& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) volatile&&, true, false>
{
typedef _Class volatile&& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) volatile&&, true, false>
{
typedef _Class volatile&& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const volatile&&, true, false>
{
typedef _Class const volatile&& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param...);
};
template <class _Rp, class _Class, class ..._Param>
struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const volatile&&, true, false>
{
typedef _Class const volatile&& _ClassType;
typedef _Rp _ReturnType;
typedef _Rp (_FnType) (_Param..., ...);
};
#endif // __has_feature(cxx_reference_qualified_functions) || defined(_LIBCPP_COMPILER_GCC)
template <class _Rp, class _Class>
struct __member_pointer_traits_imp<_Rp _Class::*, false, true>
{
typedef _Class _ClassType;
typedef _Rp _ReturnType;
};
template <class _MP>
struct __member_pointer_traits
: public __member_pointer_traits_imp<typename remove_cv<_MP>::type,
is_member_function_pointer<_MP>::value,
is_member_object_pointer<_MP>::value>
{
// typedef ... _ClassType;
// typedef ... _ReturnType;
// typedef ... _FnType;
};
template <class _DecayedFp>
struct __member_pointer_class_type {};
template <class _Ret, class _ClassType>
struct __member_pointer_class_type<_Ret _ClassType::*> {
typedef _ClassType type;
};
#ifndef _LIBCPP_CXX03_LANG
template <class _Fp, class _A0,
class _DecayFp = typename decay<_Fp>::type,
class _DecayA0 = typename decay<_A0>::type,
class _ClassT = typename __member_pointer_class_type<_DecayFp>::type>
using __enable_if_bullet1 = typename enable_if
<
is_member_function_pointer<_DecayFp>::value
&& is_base_of<_ClassT, _DecayA0>::value
>::type;
template <class _Fp, class _A0,
class _DecayFp = typename decay<_Fp>::type,
class _DecayA0 = typename decay<_A0>::type>
using __enable_if_bullet2 = typename enable_if
<
is_member_function_pointer<_DecayFp>::value
&& __is_reference_wrapper<_DecayA0>::value
>::type;
template <class _Fp, class _A0,
class _DecayFp = typename decay<_Fp>::type,
class _DecayA0 = typename decay<_A0>::type,
class _ClassT = typename __member_pointer_class_type<_DecayFp>::type>
using __enable_if_bullet3 = typename enable_if
<
is_member_function_pointer<_DecayFp>::value
&& !is_base_of<_ClassT, _DecayA0>::value
&& !__is_reference_wrapper<_DecayA0>::value
>::type;
template <class _Fp, class _A0,
class _DecayFp = typename decay<_Fp>::type,
class _DecayA0 = typename decay<_A0>::type,
class _ClassT = typename __member_pointer_class_type<_DecayFp>::type>
using __enable_if_bullet4 = typename enable_if
<
is_member_object_pointer<_DecayFp>::value
&& is_base_of<_ClassT, _DecayA0>::value
>::type;
template <class _Fp, class _A0,
class _DecayFp = typename decay<_Fp>::type,
class _DecayA0 = typename decay<_A0>::type>
using __enable_if_bullet5 = typename enable_if
<
is_member_object_pointer<_DecayFp>::value
&& __is_reference_wrapper<_DecayA0>::value
>::type;
template <class _Fp, class _A0,
class _DecayFp = typename decay<_Fp>::type,
class _DecayA0 = typename decay<_A0>::type,
class _ClassT = typename __member_pointer_class_type<_DecayFp>::type>
using __enable_if_bullet6 = typename enable_if
<
is_member_object_pointer<_DecayFp>::value
&& !is_base_of<_ClassT, _DecayA0>::value
&& !__is_reference_wrapper<_DecayA0>::value
>::type;
// __invoke forward declarations
// fall back - none of the bullets
template <class ..._Args>
auto __invoke(__any, _Args&& ...__args) -> __nat;
// bullets 1, 2 and 3
template <class _Fp, class _A0, class ..._Args,
class = __enable_if_bullet1<_Fp, _A0>>
inline _LIBCPP_INLINE_VISIBILITY
constexpr auto
__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
noexcept(noexcept((static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...)))
-> decltype( (static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...))
{ return (static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...); }
template <class _Fp, class _A0, class ..._Args,
class = __enable_if_bullet2<_Fp, _A0>>
inline _LIBCPP_INLINE_VISIBILITY
constexpr auto
__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
noexcept(noexcept((__a0.get().*__f)(static_cast<_Args&&>(__args)...)))
-> decltype( (__a0.get().*__f)(static_cast<_Args&&>(__args)...))
{ return (__a0.get().*__f)(static_cast<_Args&&>(__args)...); }
template <class _Fp, class _A0, class ..._Args,
class = __enable_if_bullet3<_Fp, _A0>>
inline _LIBCPP_INLINE_VISIBILITY
constexpr auto
__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
noexcept(noexcept(((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...)))
-> decltype( ((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...))
{ return ((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...); }
// bullets 4, 5 and 6
template <class _Fp, class _A0,
class = __enable_if_bullet4<_Fp, _A0>>
inline _LIBCPP_INLINE_VISIBILITY
constexpr auto
__invoke(_Fp&& __f, _A0&& __a0)
noexcept(noexcept(static_cast<_A0&&>(__a0).*__f))
-> decltype( static_cast<_A0&&>(__a0).*__f)
{ return static_cast<_A0&&>(__a0).*__f; }
template <class _Fp, class _A0,
class = __enable_if_bullet5<_Fp, _A0>>
inline _LIBCPP_INLINE_VISIBILITY
constexpr auto
__invoke(_Fp&& __f, _A0&& __a0)
noexcept(noexcept(__a0.get().*__f))
-> decltype( __a0.get().*__f)
{ return __a0.get().*__f; }
template <class _Fp, class _A0,
class = __enable_if_bullet6<_Fp, _A0>>
inline _LIBCPP_INLINE_VISIBILITY
constexpr auto
__invoke(_Fp&& __f, _A0&& __a0)
noexcept(noexcept((*static_cast<_A0&&>(__a0)).*__f))
-> decltype( (*static_cast<_A0&&>(__a0)).*__f)
{ return (*static_cast<_A0&&>(__a0)).*__f; }
// bullet 7
template <class _Fp, class ..._Args>
inline _LIBCPP_INLINE_VISIBILITY
constexpr auto
__invoke(_Fp&& __f, _Args&& ...__args)
noexcept(noexcept(static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...)))
-> decltype( static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...))
{ return static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...); }
// __invokable
template <class _Ret, class _Fp, class ..._Args>
struct __invokable_r
{
template <class _XFp, class ..._XArgs>
static auto __try_call(int) -> decltype(
_VSTD::__invoke(declval<_XFp>(), declval<_XArgs>()...));
template <class _XFp, class ..._XArgs>
static __nat __try_call(...);
// FIXME: Check that _Ret, _Fp, and _Args... are all complete types, cv void,
// or incomplete array types as required by the standard.
using _Result = decltype(__try_call<_Fp, _Args...>(0));
using type = typename conditional<
_IsNotSame<_Result, __nat>::value,
typename conditional< is_void<_Ret>::value, true_type, __is_core_convertible<_Result, _Ret> >::type,
false_type >::type;
static const bool value = type::value;
};
template <class _Fp, class ..._Args>
using __invokable = __invokable_r<void, _Fp, _Args...>;
template <bool _IsInvokable, bool _IsCVVoid, class _Ret, class _Fp, class ..._Args>
struct __nothrow_invokable_r_imp {
static const bool value = false;
};
template <class _Ret, class _Fp, class ..._Args>
struct __nothrow_invokable_r_imp<true, false, _Ret, _Fp, _Args...>
{
typedef __nothrow_invokable_r_imp _ThisT;
template <class _Tp>
static void __test_noexcept(_Tp) noexcept;
static const bool value = noexcept(_ThisT::__test_noexcept<_Ret>(
_VSTD::__invoke(declval<_Fp>(), declval<_Args>()...)));
};
template <class _Ret, class _Fp, class ..._Args>
struct __nothrow_invokable_r_imp<true, true, _Ret, _Fp, _Args...>
{
static const bool value = noexcept(
_VSTD::__invoke(declval<_Fp>(), declval<_Args>()...));
};
template <class _Ret, class _Fp, class ..._Args>
using __nothrow_invokable_r =
__nothrow_invokable_r_imp<
__invokable_r<_Ret, _Fp, _Args...>::value,
is_void<_Ret>::value,
_Ret, _Fp, _Args...
>;
template <class _Fp, class ..._Args>
using __nothrow_invokable =
__nothrow_invokable_r_imp<
__invokable<_Fp, _Args...>::value,
true, void, _Fp, _Args...
>;
template <class _Fp, class ..._Args>
struct __invoke_of
: public enable_if<
__invokable<_Fp, _Args...>::value,
typename __invokable_r<void, _Fp, _Args...>::_Result>
{
};
#else
// Assume that it's a functor in C++03
template <class _Func, class... _Args>
_LIBCPP_HIDE_FROM_ABI
decltype(std::declval<_Func>()(std::declval<_Args>()...)) __invoke(_Func&& __func, _Args&&... __args) {
return static_cast<_Func&&>(__func)(static_cast<_Args&&>(__args)...);
}
template <class _Ret, class _T1, bool _IsFunc, bool _IsBase>
struct __enable_invoke_imp;
template <class _Ret, class _T1>
struct __enable_invoke_imp<_Ret, _T1, true, true> {
typedef _Ret _Bullet1;
typedef _Bullet1 type;
};
template <class _Ret, class _T1>
struct __enable_invoke_imp<_Ret, _T1, true, false> {
typedef _Ret _Bullet2;
typedef _Bullet2 type;
};
template <class _Ret, class _T1>
struct __enable_invoke_imp<_Ret, _T1, false, true> {
typedef typename add_lvalue_reference<
typename __apply_cv<_T1, _Ret>::type
>::type _Bullet3;
typedef _Bullet3 type;
};
template <class _Ret, class _T1>
struct __enable_invoke_imp<_Ret, _T1, false, false> {
typedef typename add_lvalue_reference<
typename __apply_cv<decltype(*declval<_T1>()), _Ret>::type
>::type _Bullet4;
typedef _Bullet4 type;
};
template <class _Ret, class _T1>
struct __enable_invoke_imp<_Ret, _T1*, false, false> {
typedef typename add_lvalue_reference<
typename __apply_cv<_T1, _Ret>::type
>::type _Bullet4;
typedef _Bullet4 type;
};
template <class _Fn, class _T1,
class _Traits = __member_pointer_traits<_Fn>,
class _Ret = typename _Traits::_ReturnType,
class _Class = typename _Traits::_ClassType>
struct __enable_invoke : __enable_invoke_imp<
_Ret, _T1,
is_member_function_pointer<_Fn>::value,
is_base_of<_Class, typename remove_reference<_T1>::type>::value>
{
};
__nat __invoke(__any, ...);
// first bullet
template <class _Fn, class _T1>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet1
__invoke(_Fn __f, _T1& __t1) {
return (__t1.*__f)();
}
template <class _Fn, class _T1, class _A0>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet1
__invoke(_Fn __f, _T1& __t1, _A0& __a0) {
return (__t1.*__f)(__a0);
}
template <class _Fn, class _T1, class _A0, class _A1>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet1
__invoke(_Fn __f, _T1& __t1, _A0& __a0, _A1& __a1) {
return (__t1.*__f)(__a0, __a1);
}
template <class _Fn, class _T1, class _A0, class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet1
__invoke(_Fn __f, _T1& __t1, _A0& __a0, _A1& __a1, _A2& __a2) {
return (__t1.*__f)(__a0, __a1, __a2);
}
template <class _Fn, class _T1>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet2
__invoke(_Fn __f, _T1& __t1) {
return ((*__t1).*__f)();
}
template <class _Fn, class _T1, class _A0>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet2
__invoke(_Fn __f, _T1& __t1, _A0& __a0) {
return ((*__t1).*__f)(__a0);
}
template <class _Fn, class _T1, class _A0, class _A1>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet2
__invoke(_Fn __f, _T1& __t1, _A0& __a0, _A1& __a1) {
return ((*__t1).*__f)(__a0, __a1);
}
template <class _Fn, class _T1, class _A0, class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet2
__invoke(_Fn __f, _T1& __t1, _A0& __a0, _A1& __a1, _A2& __a2) {
return ((*__t1).*__f)(__a0, __a1, __a2);
}
template <class _Fn, class _T1>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet3
__invoke(_Fn __f, _T1& __t1) {
return __t1.*__f;
}
template <class _Fn, class _T1>
inline _LIBCPP_INLINE_VISIBILITY
typename __enable_invoke<_Fn, _T1>::_Bullet4
__invoke(_Fn __f, _T1& __t1) {
return (*__t1).*__f;
}
// fifth bullet
template <class _Fp>
inline _LIBCPP_INLINE_VISIBILITY
decltype(declval<_Fp&>()())
__invoke(_Fp& __f)
{
return __f();
}
template <class _Fp, class _A0>
inline _LIBCPP_INLINE_VISIBILITY
decltype(declval<_Fp&>()(declval<_A0&>()))
__invoke(_Fp& __f, _A0& __a0)
{
return __f(__a0);
}
template <class _Fp, class _A0, class _A1>
inline _LIBCPP_INLINE_VISIBILITY
decltype(declval<_Fp&>()(declval<_A0&>(), declval<_A1&>()))
__invoke(_Fp& __f, _A0& __a0, _A1& __a1)
{
return __f(__a0, __a1);
}
template <class _Fp, class _A0, class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
decltype(declval<_Fp&>()(declval<_A0&>(), declval<_A1&>(), declval<_A2&>()))
__invoke(_Fp& __f, _A0& __a0, _A1& __a1, _A2& __a2)
{
return __f(__a0, __a1, __a2);
}
#endif // _LIBCPP_CXX03_LANG
template <class _Ret, bool = is_void<_Ret>::value>
struct __invoke_void_return_wrapper
{
#ifndef _LIBCPP_CXX03_LANG
template <class ..._Args>
static _Ret __call(_Args&&... __args) {
return _VSTD::__invoke(_VSTD::forward<_Args>(__args)...);
}
#else
template <class _Fn>
static _Ret __call(_Fn __f) {
return _VSTD::__invoke(__f);
}
template <class _Fn, class _A0>
static _Ret __call(_Fn __f, _A0& __a0) {
return _VSTD::__invoke(__f, __a0);
}
template <class _Fn, class _A0, class _A1>
static _Ret __call(_Fn __f, _A0& __a0, _A1& __a1) {
return _VSTD::__invoke(__f, __a0, __a1);
}
template <class _Fn, class _A0, class _A1, class _A2>
static _Ret __call(_Fn __f, _A0& __a0, _A1& __a1, _A2& __a2){
return _VSTD::__invoke(__f, __a0, __a1, __a2);
}
#endif
};
template <class _Ret>
struct __invoke_void_return_wrapper<_Ret, true>
{
#ifndef _LIBCPP_CXX03_LANG
template <class ..._Args>
static void __call(_Args&&... __args) {
_VSTD::__invoke(_VSTD::forward<_Args>(__args)...);
}
#else
template <class _Fn>
static void __call(_Fn __f) {
_VSTD::__invoke(__f);
}
template <class _Fn, class _A0>
static void __call(_Fn __f, _A0& __a0) {
_VSTD::__invoke(__f, __a0);
}
template <class _Fn, class _A0, class _A1>
static void __call(_Fn __f, _A0& __a0, _A1& __a1) {
_VSTD::__invoke(__f, __a0, __a1);
}
template <class _Fn, class _A0, class _A1, class _A2>
static void __call(_Fn __f, _A0& __a0, _A1& __a1, _A2& __a2) {
_VSTD::__invoke(__f, __a0, __a1, __a2);
}
#endif
};
#if _LIBCPP_STD_VER > 14
// is_invocable
template <class _Fn, class ..._Args>
struct _LIBCPP_TEMPLATE_VIS is_invocable
: integral_constant<bool, __invokable<_Fn, _Args...>::value> {};
template <class _Ret, class _Fn, class ..._Args>
struct _LIBCPP_TEMPLATE_VIS is_invocable_r
: integral_constant<bool, __invokable_r<_Ret, _Fn, _Args...>::value> {};
template <class _Fn, class ..._Args>
inline constexpr bool is_invocable_v = is_invocable<_Fn, _Args...>::value;
template <class _Ret, class _Fn, class ..._Args>
inline constexpr bool is_invocable_r_v = is_invocable_r<_Ret, _Fn, _Args...>::value;
// is_nothrow_invocable
template <class _Fn, class ..._Args>
struct _LIBCPP_TEMPLATE_VIS is_nothrow_invocable
: integral_constant<bool, __nothrow_invokable<_Fn, _Args...>::value> {};
template <class _Ret, class _Fn, class ..._Args>
struct _LIBCPP_TEMPLATE_VIS is_nothrow_invocable_r
: integral_constant<bool, __nothrow_invokable_r<_Ret, _Fn, _Args...>::value> {};
template <class _Fn, class ..._Args>
inline constexpr bool is_nothrow_invocable_v = is_nothrow_invocable<_Fn, _Args...>::value;
template <class _Ret, class _Fn, class ..._Args>
inline constexpr bool is_nothrow_invocable_r_v = is_nothrow_invocable_r<_Ret, _Fn, _Args...>::value;
template <class _Fn, class... _Args>
struct _LIBCPP_TEMPLATE_VIS invoke_result
: __invoke_of<_Fn, _Args...>
{
};
template <class _Fn, class... _Args>
using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
template <class _Fn, class ..._Args>
_LIBCPP_CONSTEXPR_AFTER_CXX17 invoke_result_t<_Fn, _Args...>
invoke(_Fn&& __f, _Args&&... __args)
noexcept(is_nothrow_invocable_v<_Fn, _Args...>)
{
return _VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...);
}
#endif // _LIBCPP_STD_VER > 14
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___FUNCTIONAL_INVOKE_H