Hristo Hristov 03cda77409 [libc++][spaceship] Implement operator<=> for optional
Implements parts of **P1614R2**: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1614r2.html

- Implemented `operator<=>` for `optional`
- Updated "optional synopsis" to match the current draft https://eel.is/c++draft/optional closer
- Implemented https://cplusplus.github.io/LWG/issue3566
- Implemented https://cplusplus.github.io/LWG/issue3746

Reviewed By: #libc, philnik, ldionne

Differential Revision: https://reviews.llvm.org/D146392
2023-05-05 09:59:22 +03:00

51 lines
1.4 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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// <optional>
// [optional.nullops], comparison with nullopt
// template<class T>
// constexpr strong_ordering operator<=>(const optional<T>&, nullopt_t) noexcept;
#include <cassert>
#include <compare>
#include <optional>
#include "test_comparisons.h"
constexpr bool test() {
{
std::optional<int> op;
assert((std::nullopt <=> op) == std::strong_ordering::equal);
assert(testOrder(std::nullopt, op, std::strong_ordering::equal));
assert((op <=> std::nullopt) == std::strong_ordering::equal);
assert(testOrder(op, std::nullopt, std::strong_ordering::equal));
}
{
std::optional<int> op{1};
assert((std::nullopt <=> op) == std::strong_ordering::less);
assert(testOrder(std::nullopt, op, std::strong_ordering::less));
}
{
std::optional<int> op{1};
assert((op <=> std::nullopt) == std::strong_ordering::greater);
assert(testOrder(op, std::nullopt, std::strong_ordering::greater));
}
return true;
}
int main(int, char**) {
assert(test());
static_assert(test());
return 0;
}