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
39 lines
975 B
C++
39 lines
975 B
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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// constexpr E& error() & noexcept;
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#include <cassert>
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#include <concepts>
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#include <expected>
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#include <utility>
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template <class T>
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concept ErrorNoexcept =
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requires(T& t) {
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{ t.error() } noexcept;
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};
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static_assert(!ErrorNoexcept<int>);
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static_assert(ErrorNoexcept<std::unexpected<int>>);
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constexpr bool test() {
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std::unexpected<int> unex(5);
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decltype(auto) i = unex.error();
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static_assert(std::same_as<decltype(i), int&>);
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assert(i == 5);
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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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