unwrap_ref_decay.pass.cpp (1937B)
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_ref_decay; 14 // 15 // template <class T> 16 // using unwrap_ref_decay_t = typename unwrap_ref_decay<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 Result> 25 void check() { 26 static_assert(std::is_same_v<typename std::unwrap_ref_decay<T>::type, Result>); 27 static_assert(std::is_same_v<typename std::unwrap_ref_decay<T>::type, std::unwrap_ref_decay_t<T>>); 28 } 29 30 struct T { }; 31 32 int main() { 33 check<T, T>(); 34 check<T&, T>(); 35 check<T const, T>(); 36 check<T const&, T>(); 37 check<T*, T*>(); 38 check<T const*, T const*>(); 39 check<T[3], T*>(); 40 check<T const [3], T const*>(); 41 check<T (), T (*)()>(); 42 check<T (int) const, T (int) const>(); 43 check<T (int) &, T (int) &>(); 44 check<T (int) &&, T (int) &&>(); 45 46 check<std::reference_wrapper<T>, T&>(); 47 check<std::reference_wrapper<T>&, T&>(); 48 check<std::reference_wrapper<T const>, T const&>(); 49 check<std::reference_wrapper<T const>&, T const&>(); 50 check<std::reference_wrapper<T*>, T*&>(); 51 check<std::reference_wrapper<T*>&, T*&>(); 52 check<std::reference_wrapper<T const*>, T const*&>(); 53 check<std::reference_wrapper<T const*>&, T const*&>(); 54 check<std::reference_wrapper<T[3]>, T (&)[3]>(); 55 check<std::reference_wrapper<T[3]>&, T (&)[3]>(); 56 check<std::reference_wrapper<T ()>, T (&)()>(); 57 check<std::reference_wrapper<T ()>&, T (&)()>(); 58 }