这是C++17的currentdescriptionMoveAssignable的:t=rv;Iftandrvdonotrefertothesameobject,tisequivalenttothevalueofrvbeforetheassignmentrv'sstateisunspecified.[ Note:rvmuststillmeettherequirementsofthelibrarycomponentthatisusingit,whetherornottandrvrefertothesameobject.Theoperationslistedinthoserequireme