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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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// struct identity;
#include <functional>
#include <cassert>
#include <concepts>
#include <utility>
#include "MoveOnly.h"
static_assert(std::semiregular<std::identity>);
static_assert(requires { typename std::identity::is_transparent; });
constexpr bool test() {
std::identity id;
int i = 42;
assert(id(i) == 42);
assert(id(std::move(i)) == 42);
MoveOnly m1 = 2;
MoveOnly m2 = id(std::move(m1));
assert(m2.get() == 2);
assert(&id(i) == &i);
static_assert(&id(id) == &id);
const std::identity idc;
assert(idc(1) == 1);
assert(std::move(id)(1) == 1);
assert(std::move(idc)(1) == 1);
id = idc; // run-time checks assignment
static_assert(std::is_same_v<decltype(id(i)), int&>);
static_assert(std::is_same_v<decltype(id(std::declval<int&&>())), int&&>);
static_assert(
std::is_same_v<decltype(id(std::declval<int const&>())), int const&>);
static_assert(
std::is_same_v<decltype(id(std::declval<int const&&>())), int const&&>);
static_assert(std::is_same_v<decltype(id(std::declval<int volatile&>())),
int volatile&>);
static_assert(std::is_same_v<decltype(id(std::declval<int volatile&&>())),
int volatile&&>);
static_assert(
std::is_same_v<decltype(id(std::declval<int const volatile&>())),
int const volatile&>);
static_assert(
std::is_same_v<decltype(id(std::declval<int const volatile&&>())),
int const volatile&&>);
struct S {
constexpr S() = default;
constexpr S(S&&) noexcept(false) {}
constexpr S(S const&) noexcept(false) {}
};
S x;
static_assert(noexcept(id(x)));
static_assert(noexcept(id(S())));
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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