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 // constexpr const T& optional<T>::value() const; 13 14 #include <experimental/optional> 15 #include <type_traits> 16 #include <cassert> 17 18 #if _LIBCPP_STD_VER > 11 19 20 using std::experimental::optional; 21 22 struct X 23 { 24 constexpr int test() const {return 3;} 25 int test() {return 4;} 26 }; 27 28 #endif // _LIBCPP_STD_VER > 11 29 30 int main() 31 { 32 #if _LIBCPP_STD_VER > 11 33 { 34 constexpr optional<X> opt; 35 static_assert(opt.value().test() == 3, ""); 36 } 37 #else 38 #error 39 #endif // _LIBCPP_STD_VER > 11 40 } 41
