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 // <variant>
14 
15 // template <size_t I, class T> struct variant_alternative; // undefined
16 // template <size_t I, class T> struct variant_alternative<I, const T>;
17 // template <size_t I, class T> struct variant_alternative<I, volatile T>;
18 // template <size_t I, class T> struct variant_alternative<I, const volatile T>;
19 // template <size_t I, class T>
20 //   using variant_alternative_t = typename variant_alternative<I, T>::type;
21 //
22 // template <size_t I, class... Types>
23 //    struct variant_alternative<I, variant<Types...>>;
24 
25 #include <memory>
26 #include <type_traits>
27 #include <variant>
28 
main()29 int main() {
30     using V = std::variant<int, void *, const void *, long double>;
31     std::variant_alternative<4, V>::type foo;  // expected-error@variant:* {{Index out of bounds in std::variant_alternative<>}}
32 }
33