Let cypclass refcount functions also accept non-cypclass args and just do nothing

Cython/Compiler/Builtin.py

@@ -652,15 +652,24 @@ def init_builtin_structs():
             name, "struct", scope, 1, None, cname = cname)
 
 def inject_cypclass_refcount_macros():
-    incref_type = PyrexTypes.CFuncType(PyrexTypes.c_void_type, [PyrexTypes.CFuncTypeArg("obj", PyrexTypes.cy_object_type, None)], nogil = 1)
+    template_placeholder_type = PyrexTypes.TemplatePlaceholderType("T")
+    incref_type = PyrexTypes.CFuncType(
+        PyrexTypes.c_void_type, [PyrexTypes.CFuncTypeArg("obj", template_placeholder_type, None)],
+        nogil = 1,
+        templates = [template_placeholder_type]
+    )
 
-    # The decref macros set their argument to NULL when the counter reaches 0,
-    # so we pretend to Cython that it's a c++ function with the argument passed by reference.
-    # This keeps the compiler from using std::move when calling the macro for instance.
-    reference_to_cy_object_type = PyrexTypes.CReferenceType(PyrexTypes.cy_object_type)
-    decref_type = PyrexTypes.CFuncType(PyrexTypes.c_void_type, [PyrexTypes.CFuncTypeArg("obj", reference_to_cy_object_type, None)], nogil = 1)
+    reference_to_template_type = PyrexTypes.CReferenceType(template_placeholder_type)
+    decref_type = PyrexTypes.CFuncType(
+        PyrexTypes.c_void_type, [PyrexTypes.CFuncTypeArg("obj", reference_to_template_type, None)],
+        nogil = 1,
+        templates = [template_placeholder_type]
+    )
 
-    getref_type = PyrexTypes.CFuncType(PyrexTypes.c_int_type, [PyrexTypes.CFuncTypeArg("obj", PyrexTypes.cy_object_type, None)], nogil = 1)
+    getref_type = PyrexTypes.CFuncType(
+        PyrexTypes.c_int_type, [PyrexTypes.CFuncTypeArg("obj", PyrexTypes.cy_object_type, None)],
+        nogil = 1,
+    )
 
     for macro, macro_type in [("Cy_INCREF", incref_type), ("Cy_DECREF", decref_type), ("Cy_XDECREF", decref_type), ("Cy_GETREF", getref_type)]:
         builtin_scope.declare_builtin_cfunction(macro, macro_type, macro)

Cython/Utility/CyObjects.cpp

@@ -123,12 +123,38 @@
       virtual ~ActhonActivableClass();
     };
 
-    static inline int _Cy_DECREF(CyObject *op) {
-        return op->CyObject_DECREF();
+
+    /*
+     * Let Cy_INCREF, Cy_DECREF and Cy_XDECREF accept any argument type
+     * but only do the work when the argument is actually a CyObject
+     */
+    template <typename T, typename std::enable_if<!std::is_convertible<T, CyObject*>::value, int>::type = 0>
+    static inline void Cy_DECREF(T) {}
+
+    template <typename T, typename std::enable_if<!std::is_convertible<T, CyObject*>::value, int>::type = 0>
+    static inline void Cy_XDECREF(T) {}
+
+    template <typename T, typename std::enable_if<!std::is_convertible<T, CyObject*>::value, int>::type = 0>
+    static inline void Cy_INCREF(T) {}
+
+    template <typename T, typename std::enable_if<std::is_convertible<T, CyObject*>::value, int>::type = 0>
+    static inline void Cy_DECREF(T &op) {
+        if(op->CyObject_DECREF())
+            op = NULL;
     }
 
-    static inline void _Cy_INCREF(CyObject *op) {
-        op->CyObject_INCREF();
+    template <typename T, typename std::enable_if<std::is_convertible<T, CyObject*>::value, int>::type = 0>
+    static inline void Cy_XDECREF(T &op) {
+        if (op != NULL) {
+            if(op->CyObject_DECREF())
+            op = NULL;
+        }
+    }
+
+    template <typename T, typename std::enable_if<std::is_convertible<T, CyObject*>::value, int>::type = 0>
+    static inline void Cy_INCREF(T op) {
+        if (op != NULL)
+            op->CyObject_INCREF();
     }
 
     static inline int _Cy_GETREF(CyObject *op) {
@@ -241,12 +267,10 @@
         return underlying;
     }
 
+
     /* Cast argument to CyObject* type. */
     #define _CyObject_CAST(op) op
 
-    #define Cy_INCREF(op) do {if (op != NULL) {_Cy_INCREF(_CyObject_CAST(op));}} while(0)
-    #define Cy_DECREF(op) do {if (_Cy_DECREF(_CyObject_CAST(op))) {op = NULL;}} while(0)
-    #define Cy_XDECREF(op) do {if (op != NULL) {Cy_DECREF(op);}} while(0)
     #define Cy_GETREF(op) (_Cy_GETREF(_CyObject_CAST(op)))
     #define Cy_GOTREF(op)
     #define Cy_XGOTREF(op)