e356f681f6
Implement `std::expected` https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p0323r12.html Added tests Differential Revision: https://reviews.llvm.org/D124516 address comment
75 lines
2.1 KiB
C++
75 lines
2.1 KiB
C++
//===----------------------------------------------------------------------===//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
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// template<class T2, class E2> requires (is_void_v<T2>)
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// friend constexpr bool operator==(const expected& x, const expected<T2, E2>& y);
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#include <cassert>
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#include <concepts>
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#include <expected>
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#include <type_traits>
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#include <utility>
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#include "test_macros.h"
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// Test constraint
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template <class T1, class T2>
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concept CanCompare = requires(T1 t1, T2 t2) { t1 == t2; };
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struct Foo{};
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static_assert(!CanCompare<Foo, Foo>);
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static_assert(CanCompare<std::expected<void, int>, std::expected<void, int>>);
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static_assert(CanCompare<std::expected<void, int>, std::expected<void, short>>);
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// Note this is true because other overloads in expected<non-void> are unconstrained
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static_assert(CanCompare<std::expected<void, int>, std::expected<int, int>>);
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constexpr bool test() {
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// x.has_value() && y.has_value()
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{
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const std::expected<void, int> e1;
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const std::expected<void, int> e2;
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assert(e1 == e2);
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}
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// !x.has_value() && y.has_value()
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{
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const std::expected<void, int> e1(std::unexpect, 5);
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const std::expected<void, int> e2;
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assert(e1 != e2);
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}
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// x.has_value() && !y.has_value()
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{
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const std::expected<void, int> e1;
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const std::expected<void, int> e2(std::unexpect, 10);
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const std::expected<void, int> e3(std::unexpect, 5);
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assert(e1 != e2);
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assert(e1 != e3);
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}
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// !x.has_value() && !y.has_value()
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{
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const std::expected<void, int> e1(std::unexpect, 5);
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const std::expected<void, int> e2(std::unexpect, 10);
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const std::expected<void, int> e3(std::unexpect, 5);
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assert(e1 != e2);
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assert(e1 == e3);
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}
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return true;
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}
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int main(int, char**) {
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test();
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static_assert(test());
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return 0;
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}
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