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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(const expected& rhs);
//
// Effects: If rhs.has_value() is true, direct-non-list-initializes val with *rhs.
// Otherwise, direct-non-list-initializes unex with rhs.error().
//
// Postconditions: rhs.has_value() == this->has_value().
//
// Throws: Any exception thrown by the initialization of val or unex.
//
// Remarks: This constructor is defined as deleted unless
// - is_copy_constructible_v<T> is true and
// - is_copy_constructible_v<E> is true.
//
// This constructor is trivial if
// - is_trivially_copy_constructible_v<T> is true and
// - is_trivially_copy_constructible_v<E> is true.
#include <cassert>
#include <expected>
#include <type_traits>
#include <utility>
#include "test_macros.h"
struct NonCopyable {
NonCopyable(const NonCopyable&) = delete;
};
struct CopyableNonTrivial {
int i;
constexpr CopyableNonTrivial(int ii) : i(ii) {}
constexpr CopyableNonTrivial(const CopyableNonTrivial& o) { i = o.i; }
friend constexpr bool operator==(const CopyableNonTrivial&, const CopyableNonTrivial&) = default;
};
// Test: This constructor is defined as deleted unless
// - is_copy_constructible_v<T> is true and
// - is_copy_constructible_v<E> is true.
static_assert(std::is_copy_constructible_v<std::expected<int, int>>);
static_assert(std::is_copy_constructible_v<std::expected<CopyableNonTrivial, int>>);
static_assert(std::is_copy_constructible_v<std::expected<int, CopyableNonTrivial>>);
static_assert(std::is_copy_constructible_v<std::expected<CopyableNonTrivial, CopyableNonTrivial>>);
static_assert(!std::is_copy_constructible_v<std::expected<NonCopyable, int>>);
static_assert(!std::is_copy_constructible_v<std::expected<int, NonCopyable>>);
static_assert(!std::is_copy_constructible_v<std::expected<NonCopyable, NonCopyable>>);
// Test: This constructor is trivial if
// - is_trivially_copy_constructible_v<T> is true and
// - is_trivially_copy_constructible_v<E> is true.
static_assert(std::is_trivially_copy_constructible_v<std::expected<int, int>>);
static_assert(!std::is_trivially_copy_constructible_v<std::expected<CopyableNonTrivial, int>>);
static_assert(!std::is_trivially_copy_constructible_v<std::expected<int, CopyableNonTrivial>>);
static_assert(!std::is_trivially_copy_constructible_v<std::expected<CopyableNonTrivial, CopyableNonTrivial>>);
constexpr bool test() {
// copy the value non-trivial
{
const std::expected<CopyableNonTrivial, int> e1(5);
auto e2 = e1;
assert(e2.has_value());
assert(e2.value().i == 5);
}
// copy the error non-trivial
{
const std::expected<int, CopyableNonTrivial> e1(std::unexpect, 5);
auto e2 = e1;
assert(!e2.has_value());
assert(e2.error().i == 5);
}
// copy the value trivial
{
const std::expected<int, int> e1(5);
auto e2 = e1;
assert(e2.has_value());
assert(e2.value() == 5);
}
// copy the error trivial
{
const std::expected<int, int> e1(std::unexpect, 5);
auto e2 = e1;
assert(!e2.has_value());
assert(e2.error() == 5);
}
return true;
}
void testException() {
#ifndef TEST_HAS_NO_EXCEPTIONS
struct Except {};
struct Throwing {
Throwing() = default;
Throwing(const Throwing&) { throw Except{}; }
};
// throw on copying value
{
const std::expected<Throwing, int> e1;
try {
[[maybe_unused]] auto e2 = e1;
assert(false);
} catch (Except) {
}
}
// throw on copying error
{
const std::expected<int, Throwing> e1(std::unexpect);
try {
[[maybe_unused]] auto e2 = e1;
assert(false);
} catch (Except) {
}
}
#endif // TEST_HAS_NO_EXCEPTIONS
}
int main(int, char**) {
test();
static_assert(test());
testException();
return 0;
}
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