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//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// <functional>
//
// template <class T>
// struct unwrap_ref_decay;
//
// template <class T>
// using unwrap_ref_decay_t = typename unwrap_ref_decay<T>::type;
// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
#include <functional>
#include <type_traits>
template <typename T, typename Result>
void check() {
static_assert(std::is_same_v<typename std::unwrap_ref_decay<T>::type, Result>);
static_assert(std::is_same_v<typename std::unwrap_ref_decay<T>::type, std::unwrap_ref_decay_t<T>>);
}
struct T { };
int main(int, char**) {
check<T, T>();
check<T&, T>();
check<T const, T>();
check<T const&, T>();
check<T*, T*>();
check<T const*, T const*>();
check<T[3], T*>();
check<T const [3], T const*>();
check<T (), T (*)()>();
check<T (int) const, T (int) const>();
check<T (int) &, T (int) &>();
check<T (int) &&, T (int) &&>();
check<std::reference_wrapper<T>, T&>();
check<std::reference_wrapper<T>&, T&>();
check<std::reference_wrapper<T const>, T const&>();
check<std::reference_wrapper<T const>&, T const&>();
check<std::reference_wrapper<T*>, T*&>();
check<std::reference_wrapper<T*>&, T*&>();
check<std::reference_wrapper<T const*>, T const*&>();
check<std::reference_wrapper<T const*>&, T const*&>();
check<std::reference_wrapper<T[3]>, T (&)[3]>();
check<std::reference_wrapper<T[3]>&, T (&)[3]>();
check<std::reference_wrapper<T ()>, T (&)()>();
check<std::reference_wrapper<T ()>&, T (&)()>();
return 0;
}
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