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// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14
// The following compilers don't generate constexpr special members correctly.
// XFAIL: clang-3.5, clang-3.6, clang-3.7, clang-3.8
// XFAIL: apple-clang-6, apple-clang-7, apple-clang-8.0
// <variant>
// template <class ...Types> class variant;
// variant& operator=(variant&&) noexcept(see below);
#include <type_traits>
#include <variant>
#include "test_macros.h"
struct NTMoveAssign {
constexpr NTMoveAssign(int v) : value(v) {}
NTMoveAssign(const NTMoveAssign &) = default;
NTMoveAssign(NTMoveAssign &&) = default;
NTMoveAssign &operator=(const NTMoveAssign &that) = default;
NTMoveAssign &operator=(NTMoveAssign &&that) {
value = that.value;
that.value = -1;
return *this;
};
int value;
};
static_assert(!std::is_trivially_move_assignable<NTMoveAssign>::value, "");
static_assert(std::is_move_assignable<NTMoveAssign>::value, "");
struct TMoveAssign {
constexpr TMoveAssign(int v) : value(v) {}
TMoveAssign(const TMoveAssign &) = delete;
TMoveAssign(TMoveAssign &&) = default;
TMoveAssign &operator=(const TMoveAssign &) = delete;
TMoveAssign &operator=(TMoveAssign &&) = default;
int value;
};
static_assert(std::is_trivially_move_assignable<TMoveAssign>::value, "");
struct TMoveAssignNTCopyAssign {
constexpr TMoveAssignNTCopyAssign(int v) : value(v) {}
TMoveAssignNTCopyAssign(const TMoveAssignNTCopyAssign &) = default;
TMoveAssignNTCopyAssign(TMoveAssignNTCopyAssign &&) = default;
TMoveAssignNTCopyAssign &operator=(const TMoveAssignNTCopyAssign &that) {
value = that.value;
return *this;
}
TMoveAssignNTCopyAssign &operator=(TMoveAssignNTCopyAssign &&) = default;
int value;
};
static_assert(std::is_trivially_move_assignable_v<TMoveAssignNTCopyAssign>, "");
void test_move_assignment_sfinae() {
{
using V = std::variant<int, long>;
static_assert(std::is_trivially_move_assignable<V>::value, "");
}
{
using V = std::variant<int, NTMoveAssign>;
static_assert(!std::is_trivially_move_assignable<V>::value, "");
static_assert(std::is_move_assignable<V>::value, "");
}
{
using V = std::variant<int, TMoveAssign>;
static_assert(std::is_trivially_move_assignable<V>::value, "");
}
{
using V = std::variant<int, TMoveAssignNTCopyAssign>;
static_assert(std::is_trivially_move_assignable<V>::value, "");
}
}
template <typename T> struct Result { size_t index; T value; };
void test_move_assignment_same_index() {
{
struct {
constexpr Result<int> operator()() const {
using V = std::variant<int>;
V v(43);
V v2(42);
v = std::move(v2);
return {v.index(), std::get<0>(v)};
}
} test;
constexpr auto result = test();
static_assert(result.index == 0, "");
static_assert(result.value == 42, "");
}
{
struct {
constexpr Result<long> operator()() const {
using V = std::variant<int, long, unsigned>;
V v(43l);
V v2(42l);
v = std::move(v2);
return {v.index(), std::get<1>(v)};
}
} test;
constexpr auto result = test();
static_assert(result.index == 1, "");
static_assert(result.value == 42l, "");
}
{
struct {
constexpr Result<int> operator()() const {
using V = std::variant<int, TMoveAssign, unsigned>;
V v(std::in_place_type<TMoveAssign>, 43);
V v2(std::in_place_type<TMoveAssign>, 42);
v = std::move(v2);
return {v.index(), std::get<1>(v).value};
}
} test;
constexpr auto result = test();
static_assert(result.index == 1, "");
static_assert(result.value == 42, "");
}
}
void test_move_assignment_different_index() {
{
struct {
constexpr Result<long> operator()() const {
using V = std::variant<int, long, unsigned>;
V v(43);
V v2(42l);
v = std::move(v2);
return {v.index(), std::get<1>(v)};
}
} test;
constexpr auto result = test();
static_assert(result.index == 1, "");
static_assert(result.value == 42l, "");
}
{
struct {
constexpr Result<long> operator()() const {
using V = std::variant<int, TMoveAssign, unsigned>;
V v(std::in_place_type<unsigned>, 43);
V v2(std::in_place_type<TMoveAssign>, 42);
v = std::move(v2);
return {v.index(), std::get<1>(v).value};
}
} test;
constexpr auto result = test();
static_assert(result.index == 1, "");
static_assert(result.value == 42, "");
}
}
template <size_t NewIdx, class ValueType>
constexpr bool test_constexpr_assign_extension_imp(
std::variant<long, void*, int>&& v, ValueType&& new_value)
{
std::variant<long, void*, int> v2(
std::forward<ValueType>(new_value));
const auto cp = v2;
v = std::move(v2);
return v.index() == NewIdx &&
std::get<NewIdx>(v) == std::get<NewIdx>(cp);
}
void test_constexpr_move_assignment_extension() {
#ifdef _LIBCPP_VERSION
using V = std::variant<long, void*, int>;
static_assert(std::is_trivially_copyable<V>::value, "");
static_assert(std::is_trivially_move_assignable<V>::value, "");
static_assert(test_constexpr_assign_extension_imp<0>(V(42l), 101l), "");
static_assert(test_constexpr_assign_extension_imp<0>(V(nullptr), 101l), "");
static_assert(test_constexpr_assign_extension_imp<1>(V(42l), nullptr), "");
static_assert(test_constexpr_assign_extension_imp<2>(V(42l), 101), "");
#endif
}
int main() {
test_move_assignment_same_index();
test_move_assignment_different_index();
test_move_assignment_sfinae();
test_constexpr_move_assignment_extension();
}
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