Question

I was just thinking what happens when we use free() with new in C++.

In case if we use free() with new then the memory could be freed. Its just the destructor will not be called. Leaving behavior something like similar to dangling pointer.

I understand that above we should not use free() with new as it may corrupt the heap.

But then also I would like to visualize the behavior conceptually.

Answer 1

Using free on memory allocated by new is undefined behavior. There’s no guarantee that new returns an address returned from malloc. (In fact, new[] often doesn’t.)