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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
// <expected>
// template<class F> constexpr auto or_else(F&& f) &;
// template<class F> constexpr auto or_else(F&& f) const &;
// template<class F> constexpr auto or_else(F&& f) &&;
// template<class F> constexpr auto or_else(F&& f) const &&;
#include <expected>
#include <concepts>
#include <cassert>
#include <type_traits>
#include <utility>
constexpr void test_val_types() {
// Test & overload
{
auto l = [](auto) -> std::expected<void, long> { return {}; };
std::expected<void, int> v(std::unexpected<int>(1));
std::same_as<std::expected<void, long>> decltype(auto) val = v.or_else(l);
assert(val.has_value());
}
// Test const& overload
{
auto l = [](auto) -> std::expected<void, long> { return {}; };
const std::expected<void, int> v(std::unexpected<int>(1));
std::same_as<std::expected<void, long>> decltype(auto) val = v.or_else(l);
assert(val.has_value());
}
// Test && overload
{
auto l = [](auto) -> std::expected<void, long> { return {}; };
std::expected<void, int> v(std::unexpected<int>(1));
std::same_as<std::expected<void, long>> decltype(auto) val = std::move(v).or_else(l);
assert(val.has_value());
}
// Test const&& overload
{
auto l = [](auto) -> std::expected<void, long> { return {}; };
const std::expected<void, int> v(std::unexpected<int>(1));
std::same_as<std::expected<void, long>> decltype(auto) val = std::move(v).or_else(l);
assert(val.has_value());
}
}
constexpr void test_fail() {
auto never_called = [](auto) -> std::expected<void, long> {
assert(false);
return std::expected<void, long>(std::unexpected<long>(5));
};
// Test & overload
{
std::expected<void, int> v;
std::same_as<std::expected<void, long>> decltype(auto) val = v.or_else(never_called);
assert(val.has_value());
}
// Test const& overload
{
const std::expected<void, int> v;
std::same_as<std::expected<void, long>> decltype(auto) val = v.or_else(never_called);
assert(val.has_value());
}
// Test && overload
{
std::expected<void, int> v;
std::same_as<std::expected<void, long>> decltype(auto) val = std::move(v).or_else(never_called);
assert(val.has_value());
}
// Test const&& overload
{
const std::expected<void, int> v;
std::same_as<std::expected<void, long>> decltype(auto) val = std::move(v).or_else(never_called);
assert(val.has_value());
}
}
constexpr bool test() {
test_fail();
test_val_types();
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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