//===----------------------------------------------------------------------===// // // 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. // //===----------------------------------------------------------------------===// // <utility> // template <class T> typename add_rvalue_reference<T>::type declval() noexcept; #include <utility> #include <type_traits> class A { A(const A&); A& operator=(const A&); }; int main() { #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES static_assert((std::is_same<decltype(std::declval<A>()), A&&>::value), ""); #else static_assert((std::is_same<decltype(std::declval<A>()), A>::value), ""); #endif }