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 // UNSUPPORTED: c++98, c++03, c++11, c++14 11 // <optional> 12 13 // template <class T> 14 // class optional 15 // { 16 // public: 17 // typedef T value_type; 18 // ... 19 20 #include <optional> 21 #include <type_traits> 22 23 using std::optional; 24 25 template <class Opt, class T> 26 void 27 test() 28 { 29 static_assert(std::is_same<typename Opt::value_type, T>::value, ""); 30 } 31 32 int main() 33 { 34 test<optional<int>, int>(); 35 test<optional<const int>, const int>(); 36 test<optional<double>, double>(); 37 test<optional<const double>, const double>(); 38 } 39
