diff --git a/stl/inc/functional b/stl/inc/functional
index 05df5e7de6..5038e78c9b 100644
--- a/stl/inc/functional
+++ b/stl/inc/functional
@@ -886,9 +886,9 @@ public:
 
 protected:
     template <class _Fx, class _Function>
-    using _Enable_if_callable_t =
-        enable_if_t<conjunction_v<negation<is_same<decay_t<_Fx>, _Function>>, _Is_invocable_r<_Ret, _Fx, _Types...>>,
-            int>;
+    using _Enable_if_callable_t = enable_if_t<conjunction_v<negation<is_same<_Remove_cvref_t<_Fx>, _Function>>,
+                                                  _Is_invocable_r<_Ret, decay_t<_Fx>&, _Types...>>,
+        int>;
 
     bool _Empty() const noexcept {
         return !_Getimpl();
@@ -1045,12 +1045,12 @@ public:
     }
 
 #if _USE_FUNCTION_INT_0_SFINAE
-    template <class _Fx, typename _Mybase::template _Enable_if_callable_t<_Fx&, function> = 0>
+    template <class _Fx, typename _Mybase::template _Enable_if_callable_t<_Fx, function> = 0>
 #else // ^^^ _USE_FUNCTION_INT_0_SFINAE // !_USE_FUNCTION_INT_0_SFINAE vvv
-    template <class _Fx, class = typename _Mybase::template _Enable_if_callable_t<_Fx&, function>>
+    template <class _Fx, class = typename _Mybase::template _Enable_if_callable_t<_Fx, function>>
 #endif // _USE_FUNCTION_INT_0_SFINAE
-    function(_Fx _Func) {
-        this->_Reset(_STD move(_Func));
+    function(_Fx&& _Func) {
+        this->_Reset(_STD forward<_Fx>(_Func));
     }
 
 #if _HAS_FUNCTION_ALLOCATOR_SUPPORT
@@ -1066,12 +1066,12 @@ public:
     }
 
 #if _USE_FUNCTION_INT_0_SFINAE
-    template <class _Fx, class _Alloc, typename _Mybase::template _Enable_if_callable_t<_Fx&, function> = 0>
+    template <class _Fx, class _Alloc, typename _Mybase::template _Enable_if_callable_t<_Fx, function> = 0>
 #else // ^^^ _USE_FUNCTION_INT_0_SFINAE // !_USE_FUNCTION_INT_0_SFINAE vvv
-    template <class _Fx, class _Alloc, class = typename _Mybase::template _Enable_if_callable_t<_Fx&, function>>
+    template <class _Fx, class _Alloc, class = typename _Mybase::template _Enable_if_callable_t<_Fx, function>>
 #endif // _USE_FUNCTION_INT_0_SFINAE
-    function(allocator_arg_t, const _Alloc& _Ax, _Fx _Func) {
-        this->_Reset_alloc(_STD move(_Func), _Ax);
+    function(allocator_arg_t, const _Alloc& _Ax, _Fx&& _Func) {
+        this->_Reset_alloc(_STD forward<_Fx>(_Func), _Ax);
     }
 #endif // _HAS_FUNCTION_ALLOCATOR_SUPPORT
 
@@ -1100,9 +1100,9 @@ public:
     }
 
 #if _USE_FUNCTION_INT_0_SFINAE
-    template <class _Fx, typename _Mybase::template _Enable_if_callable_t<decay_t<_Fx>&, function> = 0>
+    template <class _Fx, typename _Mybase::template _Enable_if_callable_t<_Fx, function> = 0>
 #else // ^^^ _USE_FUNCTION_INT_0_SFINAE // !_USE_FUNCTION_INT_0_SFINAE vvv
-    template <class _Fx, class = typename _Mybase::template _Enable_if_callable_t<decay_t<_Fx>&, function>>
+    template <class _Fx, class = typename _Mybase::template _Enable_if_callable_t<_Fx, function>>
 #endif // _USE_FUNCTION_INT_0_SFINAE
     function& operator=(_Fx&& _Func) {
         function(_STD forward<_Fx>(_Func)).swap(*this);