1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // The LLVM Compiler Infrastructure 5 // 6 // This file is dual licensed under the MIT and the University of Illinois Open 7 // Source Licenses. See LICENSE.TXT for details. 8 // 9 //===----------------------------------------------------------------------===// 10 11 // UNSUPPORTED: c++98, c++03, c++11, c++14 12 13 // Clang 3.8 doesn't allow constexpr variables of non-literal type 14 // XFAIL: clang-3.8, apple-clang-7, apple-clang-8 15 16 // <variant> 17 18 // template <class ...Types> class variant; 19 20 // constexpr size_t index() const noexcept; 21 22 #include <cassert> 23 #include <string> 24 #include <type_traits> 25 #include <variant> 26 27 #include "archetypes.hpp" 28 #include "test_macros.h" 29 #include "variant_test_helpers.hpp" 30 31 int main() { 32 { 33 using V = std::variant<int, ConstexprTestTypes::NoCtors>; 34 constexpr V v; 35 static_assert(v.index() == 0, ""); 36 } 37 { 38 using V = std::variant<int, long>; 39 constexpr V v(std::in_place_index<1>); 40 static_assert(v.index() == 1, ""); 41 } 42 { 43 using V = std::variant<int, std::string>; 44 V v("abc"); 45 assert(v.index() == 1); 46 v = 42; 47 assert(v.index() == 0); 48 } 49 #ifndef TEST_HAS_NO_EXCEPTIONS 50 { 51 using V = std::variant<int, MakeEmptyT>; 52 V v; 53 assert(v.index() == 0); 54 makeEmpty(v); 55 assert(v.index() == std::variant_npos); 56 } 57 #endif 58 } 59