Add rcp::create()

include/rcp.h

@@ -104,6 +104,12 @@ public:
     {
         return ptr != nullptr;
     }
+
+    template <typename... Args>
+    static rcp<T> create(Args&&... args)
+    {
+        return T::create(std::forward<Args>(args)...);
+    }
 };
 
 #define rcp_managed_root(classname) \