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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
//
// constexpr expected();
// Constraints: is_default_constructible_v<T> is true.
//
// Effects: Value-initializes val.
// Postconditions: has_value() is true.
//
// Throws: Any exception thrown by the initialization of val.
#include <cassert>
#include <expected>
#include <type_traits>
#include "test_macros.h"
struct NoDedefaultCtor {
NoDedefaultCtor() = delete;
};
// Test constraints
static_assert(std::is_default_constructible_v<std::expected<int, int>>);
static_assert(!std::is_default_constructible_v<std::expected<NoDedefaultCtor, int>>);
struct MyInt {
int i;
friend constexpr bool operator==(const MyInt&, const MyInt&) = default;
};
template <class T, class E>
constexpr void testDefaultCtor() {
std::expected<T, E> e;
assert(e.has_value());
assert(e.value() == T());
}
template <class T>
constexpr void testTypes() {
testDefaultCtor<T, int>();
testDefaultCtor<T, NoDedefaultCtor>();
}
constexpr bool test() {
testTypes<int>();
testTypes<MyInt>();
return true;
}
void testException() {
#ifndef TEST_HAS_NO_EXCEPTIONS
struct Except {};
struct Throwing {
Throwing() { throw Except{}; };
};
try {
std::expected<Throwing, int> u;
assert(false);
} catch (Except) {
}
#endif // TEST_HAS_NO_EXCEPTIONS
}
int main(int, char**) {
test();
static_assert(test());
testException();
return 0;
}
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