1 files changed, 58 insertions, 0 deletions
diff --git a/test/std/utilities/function.objects/refwrap/unwrap_ref_decay.pass.cpp b/test/std/utilities/function.objects/refwrap/unwrap_ref_decay.pass.cpp
new file mode 100644
index 0000000000000..a63dc5b15f4bd
--- /dev/null
+++ b/test/std/utilities/function.objects/refwrap/unwrap_ref_decay.pass.cpp
@@ -0,0 +1,58 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <functional>
+//
+// template <class T>
+// struct unwrap_ref_decay;
+//
+// template <class T>
+// using unwrap_ref_decay_t = typename unwrap_ref_decay<T>::type;
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+
+#include <functional>
+#include <type_traits>
+
+
+template <typename T, typename Result>
+void check() {
+  static_assert(std::is_same_v<typename std::unwrap_ref_decay<T>::type, Result>);
+  static_assert(std::is_same_v<typename std::unwrap_ref_decay<T>::type, std::unwrap_ref_decay_t<T>>);
+}
+
+struct T { };
+
+int main() {
+  check<T,             T>();
+  check<T&,            T>();
+  check<T const,       T>();
+  check<T const&,      T>();
+  check<T*,            T*>();
+  check<T const*,      T const*>();
+  check<T[3],          T*>();
+  check<T const [3],   T const*>();
+  check<T (),          T (*)()>();
+  check<T (int) const, T (int) const>();
+  check<T (int) &,     T (int) &>();
+  check<T (int) &&,    T (int) &&>();
+
+  check<std::reference_wrapper<T>,         T&>();
+  check<std::reference_wrapper<T>&,        T&>();
+  check<std::reference_wrapper<T const>,   T const&>();
+  check<std::reference_wrapper<T const>&,  T const&>();
+  check<std::reference_wrapper<T*>,        T*&>();
+  check<std::reference_wrapper<T*>&,       T*&>();
+  check<std::reference_wrapper<T const*>,  T const*&>();
+  check<std::reference_wrapper<T const*>&, T const*&>();
+  check<std::reference_wrapper<T[3]>,      T (&)[3]>();
+  check<std::reference_wrapper<T[3]>&,     T (&)[3]>();
+  check<std::reference_wrapper<T ()>,      T (&)()>();
+  check<std::reference_wrapper<T ()>&,     T (&)()>();
+}