【C++注意事项】5 Top-level const , The auto and decltype Type Specifier
top-levelconstAswe’veseen,apointerisanobjectthatcanpointtoadifferentobject.Asaresult,wecantalkindependentlyaboutwhetherapointerisconstandwhethertheobjectstowhichitcanpointareconst.weusethetop-levelcon