unwrap_reference.pass.cpp (1266B)
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 // <functional> 11 // 12 // template <class T> 13 // struct unwrap_reference; 14 // 15 // template <class T> 16 // using unwrap_reference_t = typename unwrap_reference<T>::type; 17 18 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17 19 20 #include <functional> 21 #include <type_traits> 22 23 24 template <typename T, typename Expected> 25 void check_equal() { 26 static_assert(std::is_same_v<typename std::unwrap_reference<T>::type, Expected>); 27 static_assert(std::is_same_v<typename std::unwrap_reference<T>::type, std::unwrap_reference_t<T>>); 28 } 29 30 template <typename T> 31 void check() { 32 check_equal<T, T>(); 33 check_equal<T&, T&>(); 34 check_equal<T const, T const>(); 35 check_equal<T const&, T const&>(); 36 37 check_equal<std::reference_wrapper<T>, T&>(); 38 check_equal<std::reference_wrapper<T const>, T const&>(); 39 } 40 41 struct T { }; 42 43 int main() { 44 check<T>(); 45 check<int>(); 46 check<float>(); 47 48 check<T*>(); 49 check<int*>(); 50 check<float*>(); 51 }