1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131
|
//===----------------------------------------------------------------------===//
// 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
// template<class G>
// constexpr expected& operator=(const unexpected<G>& e);
//
// Let GF be const G&
//
// Constraints: is_constructible_v<E, GF> is true and is_assignable_v<E&, GF> is true.
//
// Effects:
// - If has_value() is true, equivalent to:
// construct_at(addressof(unex), std::forward<GF>(e.error()));
// has_val = false;
// - Otherwise, equivalent to: unex = std::forward<GF>(e.error());
//
// Returns: *this.
#include <cassert>
#include <concepts>
#include <expected>
#include <type_traits>
#include <utility>
#include "../../types.h"
#include "test_macros.h"
struct NotCopyConstructible {
NotCopyConstructible(const NotCopyConstructible&) = delete;
NotCopyConstructible& operator=(const NotCopyConstructible&) = default;
};
struct NotCopyAssignable {
NotCopyAssignable(const NotCopyAssignable&) = default;
NotCopyAssignable& operator=(const NotCopyAssignable&) = delete;
};
struct MoveMayThrow {
MoveMayThrow(MoveMayThrow const&) = default;
MoveMayThrow& operator=(const MoveMayThrow&) = default;
MoveMayThrow(MoveMayThrow&&) noexcept(false) {}
MoveMayThrow& operator=(MoveMayThrow&&) noexcept(false) { return *this; }
};
// Test constraints
static_assert(std::is_assignable_v<std::expected<void, int>&, const std::unexpected<int>&>);
// !is_constructible_v<E, GF>
static_assert(
!std::is_assignable_v<std::expected<void, NotCopyConstructible>&, const std::unexpected<NotCopyConstructible>&>);
// !is_assignable_v<E&, GF>
static_assert(
!std::is_assignable_v<std::expected<void, NotCopyAssignable>&, const std::unexpected<NotCopyAssignable>&>);
constexpr bool test() {
// - If has_value() is true, equivalent to:
// construct_at(addressof(unex), std::forward<GF>(e.error()));
// has_val = false;
{
Traced::state state{};
std::expected<void, Traced> e;
std::unexpected<Traced> un(std::in_place, state, 5);
decltype(auto) x = (e = un);
static_assert(std::same_as<decltype(x), std::expected<void, Traced>&>);
assert(&x == &e);
assert(!e.has_value());
assert(e.error().data_ == 5);
assert(state.copyCtorCalled);
}
// - Otherwise, equivalent to: unex = std::forward<GF>(e.error());
{
Traced::state state1{};
Traced::state state2{};
std::expected<void, Traced> e(std::unexpect, state1, 5);
std::unexpected<Traced> un(std::in_place, state2, 10);
decltype(auto) x = (e = un);
static_assert(std::same_as<decltype(x), std::expected<void, Traced>&>);
assert(&x == &e);
assert(!e.has_value());
assert(e.error().data_ == 10);
assert(state1.copyAssignCalled);
}
// CheckForInvalidWrites
{
{
CheckForInvalidWrites<true, true> e;
std::unexpected<int> un(std::in_place, 42);
e = un;
assert(e.check());
}
{
CheckForInvalidWrites<false, true> e;
std::unexpected<bool> un(std::in_place, true);
e = un;
assert(e.check());
}
}
return true;
}
void testException() {
#ifndef TEST_HAS_NO_EXCEPTIONS
std::expected<void, ThrowOnCopyConstruct> e1(std::in_place);
std::unexpected<ThrowOnCopyConstruct> un(std::in_place);
try {
e1 = un;
assert(false);
} catch (Except) {
assert(e1.has_value());
}
#endif // TEST_HAS_NO_EXCEPTIONS
}
int main(int, char**) {
test();
static_assert(test());
testException();
return 0;
}
|