//===----------------------------------------------------------------------===// // // The LLVM Compiler Infrastructure // // This file is dual licensed under the MIT and the University of Illinois Open // Source Licenses. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // <optional> // template <class T> // constexpr // optional<typename decay<T>::type> // make_optional(T&& v); #include <experimental/optional> #include <string> #include <memory> #include <cassert> int main() { #if _LIBCPP_STD_VER > 11 using std::experimental::optional; using std::experimental::make_optional; { optional<int> opt = make_optional(2); assert(*opt == 2); } { std::string s("123"); optional<std::string> opt = make_optional(s); assert(*opt == s); } { std::string s("123"); optional<std::string> opt = make_optional(std::move(s)); assert(*opt == "123"); assert(s.empty()); } { std::unique_ptr<int> s(new int(3)); optional<std::unique_ptr<int>> opt = make_optional(std::move(s)); assert(**opt == 3); assert(s == nullptr); } #endif // _LIBCPP_STD_VER > 11 }