Thread: Segfault problems

> tmp = (cWIDGET*)realloc( this->widgets, sizeof( cWIDGET ) * this->nWidgets );

It seems like you'd need to copy over your previous cWIDGET data from array this->widgets to tmp at this point. Otherwise it's gone by the next statement.

How can a instance of the class exist with no allocated memory?

You've got the definition of a class done. You create a pointer to a class. Because the
class is defined, we know what we should be able to use. Thus we can do:

Code:

ptrtoclass->classmemberfunction( );

I don't know an easy way to word it so you'll understand it. You have to be able
to do the above. Otherwise, what would you compile? Your program doesn't know if
you've actually got anything real allocated at compile time. It's up to you to make sure
that all of your pointers point at something. The code is there just to do a job. You
tell it "When I give you a pointer to an object, access this member and do this that
and the other thing."

You have to make your pointer actually point at something, otherwise, you kill your
program when you try and dereference it, or have some other BadThing™ happen.

Quzah.

How did you allocate your first widget - did you use new or malloc/realloc ?
Remember malloc will not call a constructor, and realloc will not call the constructor for any new items it allocates space for.

Mixing new/delete and malloc/realloc/free is just wrong.

How complex is the internal structure of a cWIDGET?
If it contains internal pointers to other bits of itself (or other cWIDGETs), then bitwise copies of that memory to another location (which realloc will do from time to time) will break.