In this example no because of pointer. Where is the allocation for int* data located? It's not inside the object. You can think easily of the state of 'a' after calling move_into.

But maybe with int data[32] as a data member this is harder to reason about.

This is a way to illustrate move semantics and confusion behind what happens to the 'moved from' object.

You made the moved-to pointer point to the moved-from allocated heap data. Now nothing points to the heap data that was initially allocated by the moved-to object. So if you don't delete[] the moved-to data pointer, then you leaked 32 bytes of heap.

What happens when the program exits?

Then it doesn't matter. It matters if you run out of heap before the program exits, though.

No, you don't have to destroy the target object. You may need to destroy some of its members depending on the object implementation.

Yes, this is a memory leak.