spDeriveDown= dynamic_pointer_cast<CDerive>(spBaseDown);if(spDeriveDown == NULL)//由于会进行类型的检查,这边是返回NULLcout <<"spDeriveDown is null"<<endl;/*shared_ptr<CDerive> spDeriveDown; shared_ptr<CBase> spBaseDown; spBaseDown = make_shared<CDerive>(); spDeriveDown = dynamic_po...