+template <typename Internal_, typename Base_>
+JSClassRef CYPrivateOld<Internal_, Base_>::Class_;
+
+template <typename Internal_>
+struct CYPrivate {
+ static JSClassRef Class_;
+
+ template <typename... Args_>
+ static JSObjectRef Make(JSContextRef context, Args_ &&... args) {
+ Internal_ *internal(new Internal_(cy::Forward<Args_>(args)...));
+ JSObjectRef object(JSObjectMake(context, Class_, internal));
+ if (JSValueRef prototype = internal->GetPrototype(context))
+ CYSetPrototype(context, object, prototype);
+ return object;
+ }
+
+ template <typename Arg_>
+ static JSObjectRef Cache(JSContextRef context, Arg_ *arg) {
+ JSObjectRef global(CYGetGlobalObject(context));
+ JSObjectRef cy(CYCastJSObject(context, CYGetProperty(context, global, cy_s)));
+
+ char label[32];
+ sprintf(label, "%s%p", Internal_::Cache_, arg);
+ CYJSString name(label);
+
+ JSValueRef value(CYGetProperty(context, cy, name));
+ if (!JSValueIsUndefined(context, value))
+ return CYCastJSObject(context, value);
+
+ JSObjectRef object(Make(context, arg));
+ CYSetProperty(context, cy, name, object);
+ return object;
+ }
+
+ static Internal_ *Get(JSContextRef context, JSObjectRef object) {
+ _assert(JSValueIsObjectOfClass(context, object, Class_));
+ return static_cast<Internal_ *>(JSObjectGetPrivate(object));
+ }
+};
+
+template <typename Internal_>
+JSClassRef CYPrivate<Internal_>::Class_;
+