Thread: base class pointer to derived class objects

can you reassign a base class pointer to various derived class objects.

ie
BaseClass *ptrBaseClass=new BaseClass;
*ptrBaseClass=*ptrFirstDerivedClass;
*ptrBaseClass=*ptrSecondDerivedClass;
etc.

Originally posted by curlious

BaseClass *ptrBaseClass=new BaseClass;
*ptrBaseClass=*ptrFirstDerivedClass;
*ptrBaseClass=*ptrSecondDerivedClass;
etc.

That is called object slicing,not good.

That is correct

Code:

BaseClass *ptrBaseClass=new BaseClass;
ptrBaseClass = ptrFirstDerivedClass;
ptrBaseClass = ptrSecondDerivedClass;

Thanks!
I thought about it after I posted and wasn't sure weather *ptr could even be an l-value.

Code:

BaseClass *ptrBaseClass=new BaseClass;
ptrBaseClass = ptrFirstDerivedClass;
ptrBaseClass = ptrSecondDerivedClass;

While that is the correct way to make a base class pointer point to a derived class, it is of course a memory leak if used the way shown above, since the BaseClass object created with new will be lost without being destroyed.