1//===----------------------------------------------------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is dual licensed under the MIT and the University of Illinois Open 6// Source Licenses. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 10// <optional> 11 12// T& optional<T>::value(); 13 14#include <experimental/optional> 15#include <type_traits> 16#include <cassert> 17 18#if _LIBCPP_STD_VER > 11 19 20using std::experimental::optional; 21using std::experimental::bad_optional_access; 22 23struct X 24{ 25 X() = default; 26 X(const X&) = delete; 27 constexpr int test() const {return 3;} 28 int test() {return 4;} 29}; 30 31#endif // _LIBCPP_STD_VER > 11 32 33int main() 34{ 35#if _LIBCPP_STD_VER > 11 36 { 37 optional<X> opt; 38 opt.emplace(); 39 assert(opt.value().test() == 4); 40 } 41 { 42 optional<X> opt; 43 try 44 { 45 opt.value(); 46 assert(false); 47 } 48 catch (const bad_optional_access&) 49 { 50 } 51 } 52#endif // _LIBCPP_STD_VER > 11 53} 54