515 lines
15 KiB
C++
515 lines
15 KiB
C++
// -*- C++ -*-
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//===----------------------------------------------------------------------===//
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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++98, c++03, c++11, c++14
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// The following compilers don't generate constexpr special members correctly.
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// XFAIL: clang-3.5, clang-3.6, clang-3.7, clang-3.8
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// XFAIL: apple-clang-6, apple-clang-7, apple-clang-8.0
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// XFAIL: dylib-has-no-bad_variant_access && !libcpp-no-exceptions
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// <variant>
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// template <class ...Types> class variant;
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// variant& operator=(variant&&) noexcept(see below); // constexpr in C++20
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#include <cassert>
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#include <string>
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#include <type_traits>
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#include <utility>
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#include <variant>
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#include "test_macros.h"
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#include "variant_test_helpers.hpp"
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struct NoCopy {
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NoCopy(const NoCopy &) = delete;
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NoCopy &operator=(const NoCopy &) = default;
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};
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struct CopyOnly {
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CopyOnly(const CopyOnly &) = default;
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CopyOnly(CopyOnly &&) = delete;
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CopyOnly &operator=(const CopyOnly &) = default;
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CopyOnly &operator=(CopyOnly &&) = delete;
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};
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struct MoveOnly {
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MoveOnly(const MoveOnly &) = delete;
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MoveOnly(MoveOnly &&) = default;
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MoveOnly &operator=(const MoveOnly &) = delete;
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MoveOnly &operator=(MoveOnly &&) = default;
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};
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struct MoveOnlyNT {
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MoveOnlyNT(const MoveOnlyNT &) = delete;
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MoveOnlyNT(MoveOnlyNT &&) {}
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MoveOnlyNT &operator=(const MoveOnlyNT &) = delete;
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MoveOnlyNT &operator=(MoveOnlyNT &&) = default;
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};
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struct MoveOnlyOddNothrow {
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MoveOnlyOddNothrow(MoveOnlyOddNothrow &&) noexcept(false) {}
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MoveOnlyOddNothrow(const MoveOnlyOddNothrow &) = delete;
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MoveOnlyOddNothrow &operator=(MoveOnlyOddNothrow &&) noexcept = default;
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MoveOnlyOddNothrow &operator=(const MoveOnlyOddNothrow &) = delete;
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};
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struct MoveAssignOnly {
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MoveAssignOnly(MoveAssignOnly &&) = delete;
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MoveAssignOnly &operator=(MoveAssignOnly &&) = default;
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};
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struct MoveAssign {
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static int move_construct;
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static int move_assign;
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static void reset() { move_construct = move_assign = 0; }
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MoveAssign(int v) : value(v) {}
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MoveAssign(MoveAssign &&o) : value(o.value) {
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++move_construct;
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o.value = -1;
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}
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MoveAssign &operator=(MoveAssign &&o) {
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value = o.value;
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++move_assign;
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o.value = -1;
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return *this;
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}
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int value;
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};
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int MoveAssign::move_construct = 0;
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int MoveAssign::move_assign = 0;
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struct NTMoveAssign {
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constexpr NTMoveAssign(int v) : value(v) {}
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NTMoveAssign(const NTMoveAssign &) = default;
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NTMoveAssign(NTMoveAssign &&) = default;
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NTMoveAssign &operator=(const NTMoveAssign &that) = default;
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NTMoveAssign &operator=(NTMoveAssign &&that) {
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value = that.value;
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that.value = -1;
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return *this;
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};
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int value;
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};
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static_assert(!std::is_trivially_move_assignable<NTMoveAssign>::value, "");
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static_assert(std::is_move_assignable<NTMoveAssign>::value, "");
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struct TMoveAssign {
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constexpr TMoveAssign(int v) : value(v) {}
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TMoveAssign(const TMoveAssign &) = delete;
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TMoveAssign(TMoveAssign &&) = default;
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TMoveAssign &operator=(const TMoveAssign &) = delete;
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TMoveAssign &operator=(TMoveAssign &&) = default;
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int value;
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};
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static_assert(std::is_trivially_move_assignable<TMoveAssign>::value, "");
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struct TMoveAssignNTCopyAssign {
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constexpr TMoveAssignNTCopyAssign(int v) : value(v) {}
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TMoveAssignNTCopyAssign(const TMoveAssignNTCopyAssign &) = default;
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TMoveAssignNTCopyAssign(TMoveAssignNTCopyAssign &&) = default;
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TMoveAssignNTCopyAssign &operator=(const TMoveAssignNTCopyAssign &that) {
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value = that.value;
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return *this;
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}
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TMoveAssignNTCopyAssign &operator=(TMoveAssignNTCopyAssign &&) = default;
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int value;
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};
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static_assert(std::is_trivially_move_assignable_v<TMoveAssignNTCopyAssign>, "");
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struct TrivialCopyNontrivialMove {
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TrivialCopyNontrivialMove(TrivialCopyNontrivialMove const&) = default;
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TrivialCopyNontrivialMove(TrivialCopyNontrivialMove&&) noexcept {}
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TrivialCopyNontrivialMove& operator=(TrivialCopyNontrivialMove const&) = default;
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TrivialCopyNontrivialMove& operator=(TrivialCopyNontrivialMove&&) noexcept {
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return *this;
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}
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};
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static_assert(std::is_trivially_copy_assignable_v<TrivialCopyNontrivialMove>, "");
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static_assert(!std::is_trivially_move_assignable_v<TrivialCopyNontrivialMove>, "");
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void test_move_assignment_noexcept() {
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{
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using V = std::variant<int>;
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static_assert(std::is_nothrow_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<MoveOnly>;
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static_assert(std::is_nothrow_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, long>;
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static_assert(std::is_nothrow_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, MoveOnly>;
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static_assert(std::is_nothrow_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<MoveOnlyNT>;
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static_assert(!std::is_nothrow_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<MoveOnlyOddNothrow>;
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static_assert(!std::is_nothrow_move_assignable<V>::value, "");
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}
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}
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void test_move_assignment_sfinae() {
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{
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using V = std::variant<int, long>;
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static_assert(std::is_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, CopyOnly>;
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static_assert(std::is_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, NoCopy>;
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static_assert(!std::is_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, MoveOnly>;
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static_assert(std::is_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, MoveOnlyNT>;
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static_assert(std::is_move_assignable<V>::value, "");
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}
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{
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// variant only provides move assignment when the types also provide
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// a move constructor.
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using V = std::variant<int, MoveAssignOnly>;
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static_assert(!std::is_move_assignable<V>::value, "");
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}
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// Make sure we properly propagate triviality (see P0602R4).
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#if TEST_STD_VER > 17
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{
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using V = std::variant<int, long>;
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static_assert(std::is_trivially_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, NTMoveAssign>;
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static_assert(!std::is_trivially_move_assignable<V>::value, "");
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static_assert(std::is_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, TMoveAssign>;
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static_assert(std::is_trivially_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, TMoveAssignNTCopyAssign>;
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static_assert(std::is_trivially_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, TrivialCopyNontrivialMove>;
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static_assert(!std::is_trivially_move_assignable<V>::value, "");
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}
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{
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using V = std::variant<int, CopyOnly>;
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static_assert(std::is_trivially_move_assignable<V>::value, "");
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}
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#endif // > C++17
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}
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void test_move_assignment_empty_empty() {
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#ifndef TEST_HAS_NO_EXCEPTIONS
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using MET = MakeEmptyT;
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{
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using V = std::variant<int, long, MET>;
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V v1(std::in_place_index<0>);
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makeEmpty(v1);
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V v2(std::in_place_index<0>);
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makeEmpty(v2);
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.valueless_by_exception());
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assert(v1.index() == std::variant_npos);
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}
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#endif // TEST_HAS_NO_EXCEPTIONS
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}
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void test_move_assignment_non_empty_empty() {
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#ifndef TEST_HAS_NO_EXCEPTIONS
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using MET = MakeEmptyT;
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{
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using V = std::variant<int, MET>;
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V v1(std::in_place_index<0>, 42);
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V v2(std::in_place_index<0>);
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makeEmpty(v2);
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.valueless_by_exception());
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assert(v1.index() == std::variant_npos);
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}
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{
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using V = std::variant<int, MET, std::string>;
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V v1(std::in_place_index<2>, "hello");
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V v2(std::in_place_index<0>);
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makeEmpty(v2);
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.valueless_by_exception());
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assert(v1.index() == std::variant_npos);
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}
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#endif // TEST_HAS_NO_EXCEPTIONS
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}
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void test_move_assignment_empty_non_empty() {
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#ifndef TEST_HAS_NO_EXCEPTIONS
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using MET = MakeEmptyT;
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{
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using V = std::variant<int, MET>;
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V v1(std::in_place_index<0>);
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makeEmpty(v1);
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V v2(std::in_place_index<0>, 42);
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.index() == 0);
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assert(std::get<0>(v1) == 42);
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}
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{
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using V = std::variant<int, MET, std::string>;
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V v1(std::in_place_index<0>);
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makeEmpty(v1);
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V v2(std::in_place_type<std::string>, "hello");
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.index() == 2);
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assert(std::get<2>(v1) == "hello");
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}
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#endif // TEST_HAS_NO_EXCEPTIONS
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}
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template <typename T> struct Result { size_t index; T value; };
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void test_move_assignment_same_index() {
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{
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using V = std::variant<int>;
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V v1(43);
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V v2(42);
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.index() == 0);
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assert(std::get<0>(v1) == 42);
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}
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{
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using V = std::variant<int, long, unsigned>;
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V v1(43l);
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V v2(42l);
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.index() == 1);
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assert(std::get<1>(v1) == 42);
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}
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{
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using V = std::variant<int, MoveAssign, unsigned>;
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V v1(std::in_place_type<MoveAssign>, 43);
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V v2(std::in_place_type<MoveAssign>, 42);
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MoveAssign::reset();
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.index() == 1);
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assert(std::get<1>(v1).value == 42);
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assert(MoveAssign::move_construct == 0);
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assert(MoveAssign::move_assign == 1);
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}
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#ifndef TEST_HAS_NO_EXCEPTIONS
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using MET = MakeEmptyT;
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{
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using V = std::variant<int, MET, std::string>;
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V v1(std::in_place_type<MET>);
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MET &mref = std::get<1>(v1);
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V v2(std::in_place_type<MET>);
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try {
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v1 = std::move(v2);
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assert(false);
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} catch (...) {
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}
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assert(v1.index() == 1);
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assert(&std::get<1>(v1) == &mref);
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}
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#endif // TEST_HAS_NO_EXCEPTIONS
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// Make sure we properly propagate triviality, which implies constexpr-ness (see P0602R4).
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#if TEST_STD_VER > 17
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{
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struct {
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constexpr Result<int> operator()() const {
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using V = std::variant<int>;
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V v(43);
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V v2(42);
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v = std::move(v2);
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return {v.index(), std::get<0>(v)};
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}
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} test;
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constexpr auto result = test();
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static_assert(result.index == 0, "");
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static_assert(result.value == 42, "");
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}
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{
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struct {
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constexpr Result<long> operator()() const {
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using V = std::variant<int, long, unsigned>;
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V v(43l);
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V v2(42l);
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v = std::move(v2);
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return {v.index(), std::get<1>(v)};
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}
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} test;
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constexpr auto result = test();
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static_assert(result.index == 1, "");
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static_assert(result.value == 42l, "");
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}
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{
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struct {
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constexpr Result<int> operator()() const {
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using V = std::variant<int, TMoveAssign, unsigned>;
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V v(std::in_place_type<TMoveAssign>, 43);
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V v2(std::in_place_type<TMoveAssign>, 42);
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v = std::move(v2);
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return {v.index(), std::get<1>(v).value};
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}
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} test;
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constexpr auto result = test();
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static_assert(result.index == 1, "");
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static_assert(result.value == 42, "");
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}
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#endif // > C++17
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}
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void test_move_assignment_different_index() {
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{
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using V = std::variant<int, long, unsigned>;
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V v1(43);
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V v2(42l);
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.index() == 1);
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assert(std::get<1>(v1) == 42);
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}
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{
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using V = std::variant<int, MoveAssign, unsigned>;
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V v1(std::in_place_type<unsigned>, 43);
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V v2(std::in_place_type<MoveAssign>, 42);
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MoveAssign::reset();
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.index() == 1);
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assert(std::get<1>(v1).value == 42);
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assert(MoveAssign::move_construct == 1);
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assert(MoveAssign::move_assign == 0);
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}
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#ifndef TEST_HAS_NO_EXCEPTIONS
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using MET = MakeEmptyT;
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{
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using V = std::variant<int, MET, std::string>;
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V v1(std::in_place_type<int>);
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V v2(std::in_place_type<MET>);
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try {
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v1 = std::move(v2);
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assert(false);
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} catch (...) {
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}
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assert(v1.valueless_by_exception());
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assert(v1.index() == std::variant_npos);
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}
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{
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using V = std::variant<int, MET, std::string>;
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V v1(std::in_place_type<MET>);
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V v2(std::in_place_type<std::string>, "hello");
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V &vref = (v1 = std::move(v2));
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assert(&vref == &v1);
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assert(v1.index() == 2);
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assert(std::get<2>(v1) == "hello");
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}
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#endif // TEST_HAS_NO_EXCEPTIONS
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// Make sure we properly propagate triviality, which implies constexpr-ness (see P0602R4).
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#if TEST_STD_VER > 17
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{
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struct {
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constexpr Result<long> operator()() const {
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using V = std::variant<int, long, unsigned>;
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V v(43);
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V v2(42l);
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v = std::move(v2);
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return {v.index(), std::get<1>(v)};
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}
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} test;
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constexpr auto result = test();
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static_assert(result.index == 1, "");
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static_assert(result.value == 42l, "");
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}
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{
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struct {
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constexpr Result<long> operator()() const {
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using V = std::variant<int, TMoveAssign, unsigned>;
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V v(std::in_place_type<unsigned>, 43);
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V v2(std::in_place_type<TMoveAssign>, 42);
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v = std::move(v2);
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return {v.index(), std::get<1>(v).value};
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}
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} test;
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constexpr auto result = test();
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static_assert(result.index == 1, "");
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static_assert(result.value == 42, "");
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}
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#endif // > C++17
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}
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template <size_t NewIdx, class ValueType>
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constexpr bool test_constexpr_assign_imp(
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std::variant<long, void*, int>&& v, ValueType&& new_value)
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{
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std::variant<long, void*, int> v2(
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std::forward<ValueType>(new_value));
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const auto cp = v2;
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v = std::move(v2);
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return v.index() == NewIdx &&
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std::get<NewIdx>(v) == std::get<NewIdx>(cp);
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}
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void test_constexpr_move_assignment() {
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// Make sure we properly propagate triviality, which implies constexpr-ness (see P0602R4).
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#if TEST_STD_VER > 17
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using V = std::variant<long, void*, int>;
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static_assert(std::is_trivially_copyable<V>::value, "");
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static_assert(std::is_trivially_move_assignable<V>::value, "");
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static_assert(test_constexpr_assign_imp<0>(V(42l), 101l), "");
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static_assert(test_constexpr_assign_imp<0>(V(nullptr), 101l), "");
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static_assert(test_constexpr_assign_imp<1>(V(42l), nullptr), "");
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static_assert(test_constexpr_assign_imp<2>(V(42l), 101), "");
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#endif // > C++17
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}
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int main(int, char**) {
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test_move_assignment_empty_empty();
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test_move_assignment_non_empty_empty();
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test_move_assignment_empty_non_empty();
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test_move_assignment_same_index();
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test_move_assignment_different_index();
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test_move_assignment_sfinae();
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test_move_assignment_noexcept();
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test_constexpr_move_assignment();
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return 0;
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}
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