Question

int* func()
{
   int* i=new int[1];
   //do something
   return i; 
}

void funcc()
{
   int* tmp=func();
   //delete allocated memory after use
   delete tmp;
}

should delete working as described in the second function be a correct use ?
I think I didn’t allocate memory to it by new ? new was used in the first, to be sure.

Answer 1

As others have stated, you should use delete[] to delete arrays, not delete.

But, if you’re asking whether it’s okay to delete tmp because the memory it points to wasn’t allocated with new, then your premise is incorrect.

It was allocated with new. The address of the memory that you allocate within the function for i is passed back to be stored in tmp, so it does point to memory that was allocated by new.

You’re correct that i itself is out of scope at that point but memory allocated by new survives the scope change on exit from the function. And, since you’re storing its location into tmp, you still have access to it.

Hence the deletion (once you make it an array deletion with []) is quite valid.