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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, c++20
// template<class T2, class E2> requires (is_void_v<T2>)
// friend constexpr bool operator==(const expected& x, const expected<T2, E2>& y);
#include <cassert>
#include <concepts>
#include <expected>
#include <type_traits>
#include <utility>
#include "test_macros.h"
// Test constraint
template <class T1, class T2>
concept CanCompare = requires(T1 t1, T2 t2) { t1 == t2; };
struct Foo{};
static_assert(!CanCompare<Foo, Foo>);
static_assert(CanCompare<std::expected<void, int>, std::expected<void, int>>);
static_assert(CanCompare<std::expected<void, int>, std::expected<void, short>>);
// Note this is true because other overloads in expected<non-void> are unconstrained
static_assert(CanCompare<std::expected<void, int>, std::expected<int, int>>);
constexpr bool test() {
// x.has_value() && y.has_value()
{
const std::expected<void, int> e1;
const std::expected<void, int> e2;
assert(e1 == e2);
}
// !x.has_value() && y.has_value()
{
const std::expected<void, int> e1(std::unexpect, 5);
const std::expected<void, int> e2;
assert(e1 != e2);
}
// x.has_value() && !y.has_value()
{
const std::expected<void, int> e1;
const std::expected<void, int> e2(std::unexpect, 10);
const std::expected<void, int> e3(std::unexpect, 5);
assert(e1 != e2);
assert(e1 != e3);
}
// !x.has_value() && !y.has_value()
{
const std::expected<void, int> e1(std::unexpect, 5);
const std::expected<void, int> e2(std::unexpect, 10);
const std::expected<void, int> e3(std::unexpect, 5);
assert(e1 != e2);
assert(e1 == e3);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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