unittest: Explicitly extract shared_ptr to avoid ambiguity

between shared_ptr& and shared_ptr

Author: wxmerkt

unittest/bind_virtual_factory.cpp

@@ -72,7 +72,10 @@ struct VirtualClassWrapper : MyVirtualClass, bp::wrapper<MyVirtualClass> {
   }
 
   shared_ptr<MyVirtualData> createData() const override {
-    if (bp::override fo = this->get_override("createData")) return fo();
+    if (bp::override fo = this->get_override("createData")) {
+      bp::object result = fo();
+      return bp::extract<shared_ptr<MyVirtualData>>(result);
+    }
     return default_createData();
   }