a0c00ccd5f
Updates the implementation `std::reference_wrapper` - [P2944R3](https://wg21.link/P2944R3) as discussed in https://github.com/llvm/llvm-project/pull/117664#discussion_r1857826166 This PR also refactors the tests in preparation to implements the constrained comparisons for `optional`, `variant` etc. - Moves the test helpers (concepts and types) for testing constrained comparisons to `test_comparisons.h`. - Updates the `std::reference_wrapper` implementation to use the concept `__core_convertible_to<bool>` as per comments in #135759. Closes #138233 # References: - [refwrap.comparisons](https://wg21.link/refwrap.comparisons) --------- Co-authored-by: Hristo Hristov <zingam@outlook.com> Co-authored-by: Nikolas Klauser <nikolasklauser@berlin.de>
65 lines
1.5 KiB
C++
65 lines
1.5 KiB
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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// REQUIRES: std-at-least-c++26
|
|
|
|
// <functional>
|
|
|
|
// class reference_wrapper
|
|
|
|
// [refwrap.comparisons], comparisons
|
|
|
|
// friend constexpr bool operator==(reference_wrapper, reference_wrapper<const T>); // Since C++26
|
|
|
|
#include <cassert>
|
|
#include <concepts>
|
|
#include <functional>
|
|
|
|
#include "test_comparisons.h"
|
|
#include "test_macros.h"
|
|
|
|
// Test SFINAE.
|
|
|
|
static_assert(
|
|
HasOperatorEqual<std::reference_wrapper<EqualityComparable>, std::reference_wrapper<const EqualityComparable>>);
|
|
|
|
static_assert(
|
|
!HasOperatorEqual<std::reference_wrapper<EqualityComparable>, std::reference_wrapper<const NonComparable>>);
|
|
|
|
// Test equality.
|
|
|
|
template <typename T>
|
|
constexpr void test() {
|
|
T i{92};
|
|
T j{84};
|
|
|
|
std::reference_wrapper<T> rw1{i};
|
|
|
|
std::reference_wrapper<T> rw3{j};
|
|
std::reference_wrapper<const T> crw1{i};
|
|
std::reference_wrapper<const T> crw3{j};
|
|
|
|
AssertEqualityReturnBool<decltype(rw1), decltype(crw1)>();
|
|
assert(testEquality(rw1, crw1, true));
|
|
assert(testEquality(rw1, crw3, false));
|
|
}
|
|
|
|
constexpr bool test() {
|
|
test<int>();
|
|
test<EqualityComparable>();
|
|
|
|
return true;
|
|
}
|
|
|
|
int main(int, char**) {
|
|
test();
|
|
static_assert(test());
|
|
|
|
return 0;
|
|
}
|