6a54dfbfe5
Also standardize the license comment in several files where it was different from what we normally do.
106 lines
2.7 KiB
C++
106 lines
2.7 KiB
C++
//===----------------------------------------------------------------------===//
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//
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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... Args>
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// constexpr T& emplace(Args&&... args) noexcept;
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// Constraints: is_nothrow_constructible_v<T, Args...> is true.
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//
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// Effects: Equivalent to:
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// if (has_value()) {
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// destroy_at(addressof(val));
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// } else {
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// destroy_at(addressof(unex));
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// has_val = true;
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// }
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// return *construct_at(addressof(val), std::forward<Args>(args)...);
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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 "../../types.h"
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#include "test_macros.h"
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template <class T, class... Args>
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concept CanEmplace = requires(T t, Args&&... args) { t.emplace(std::forward<Args>(args)...); };
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static_assert(CanEmplace<std::expected<int, int>, int>);
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template <bool Noexcept>
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struct CtorFromInt {
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CtorFromInt(int) noexcept(Noexcept);
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CtorFromInt(int, int) noexcept(Noexcept);
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};
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static_assert(CanEmplace<std::expected<CtorFromInt<true>, int>, int>);
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static_assert(CanEmplace<std::expected<CtorFromInt<true>, int>, int, int>);
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static_assert(!CanEmplace<std::expected<CtorFromInt<false>, int>, int>);
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static_assert(!CanEmplace<std::expected<CtorFromInt<false>, int>, int, int>);
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constexpr bool test() {
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// has_value
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{
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BothNoexcept::state oldState{};
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BothNoexcept::state newState{};
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std::expected<BothNoexcept, int> e(std::in_place, oldState, 5);
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decltype(auto) x = e.emplace(newState, 10);
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static_assert(std::same_as<decltype(x), BothNoexcept&>);
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assert(&x == &(*e));
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assert(oldState.dtorCalled);
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assert(e.has_value());
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assert(e.value().data_ == 10);
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}
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// !has_value
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{
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BothMayThrow::state oldState{};
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std::expected<int, BothMayThrow> e(std::unexpect, oldState, 5);
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decltype(auto) x = e.emplace(10);
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static_assert(std::same_as<decltype(x), int&>);
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assert(&x == &(*e));
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assert(oldState.dtorCalled);
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assert(e.has_value());
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assert(e.value() == 10);
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}
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// TailClobberer
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{
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std::expected<TailClobberer<0>, bool> e(std::unexpect);
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e.emplace();
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assert(e.has_value());
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}
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// CheckForInvalidWrites
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{
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{
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CheckForInvalidWrites<true> e;
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e.emplace();
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assert(e.check());
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}
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{
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CheckForInvalidWrites<false> e;
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e.emplace();
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assert(e.check());
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}
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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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