62 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++1410 11// <variant>12 13// template <class ...Types> class variant;14 15// constexpr size_t index() const noexcept;16 17#include <cassert>18#include <string>19#include <type_traits>20#include <variant>21 22#include "archetypes.h"23#include "test_macros.h"24#include "variant_test_helpers.h"25 26 27int main(int, char**) {28 {29 using V = std::variant<int, long>;30 constexpr V v;31 static_assert(v.index() == 0, "");32 }33 {34 using V = std::variant<int, long>;35 V v;36 assert(v.index() == 0);37 }38 {39 using V = std::variant<int, long>;40 constexpr V v(std::in_place_index<1>);41 static_assert(v.index() == 1, "");42 }43 {44 using V = std::variant<int, std::string>;45 V v("abc");46 assert(v.index() == 1);47 v = 42;48 assert(v.index() == 0);49 }50#ifndef TEST_HAS_NO_EXCEPTIONS51 {52 using V = std::variant<int, MakeEmptyT>;53 V v;54 assert(v.index() == 0);55 makeEmpty(v);56 assert(v.index() == std::variant_npos);57 }58#endif59 60 return 0;61}62