65 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// REQUIRES: std-at-least-c++2610 11// <functional>12 13// class reference_wrapper14 15// [refwrap.comparisons], comparisons16 17// friend constexpr bool operator==(reference_wrapper, reference_wrapper<const T>); // Since C++2618 19#include <cassert>20#include <concepts>21#include <functional>22 23#include "test_comparisons.h"24#include "test_macros.h"25 26// Test SFINAE.27 28static_assert(29 HasOperatorEqual<std::reference_wrapper<EqualityComparable>, std::reference_wrapper<const EqualityComparable>>);30 31static_assert(32 !HasOperatorEqual<std::reference_wrapper<EqualityComparable>, std::reference_wrapper<const NonComparable>>);33 34// Test equality.35 36template <typename T>37constexpr void test() {38 T i{92};39 T j{84};40 41 std::reference_wrapper<T> rw1{i};42 43 std::reference_wrapper<T> rw3{j};44 std::reference_wrapper<const T> crw1{i};45 std::reference_wrapper<const T> crw3{j};46 47 AssertEqualityReturnBool<decltype(rw1), decltype(crw1)>();48 assert(testEquality(rw1, crw1, true));49 assert(testEquality(rw1, crw3, false));50}51 52constexpr bool test() {53 test<int>();54 test<EqualityComparable>();55 56 return true;57}58 59int main(int, char**) {60 test();61 static_assert(test());62 63 return 0;64}65