//===----------------------------------------------------------------------===// // // 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. // //===----------------------------------------------------------------------===// // UNSUPPORTED: c++98, c++03, c++11, c++14 // <optional> // constexpr const T& optional<T>::value() const &; #include <optional> #include <type_traits> #include <cassert> using std::optional; struct X { constexpr int test() const {return 3;} int test() {return 4;} }; int main() { { constexpr optional<X> opt; static_assert(opt.value().test() == 3, ""); } }