Question

If I have a function that takes in a pointer which should never be NULL, I usually do something like this:

void Foo(const somePointer* ptr)
{
  if (ptr == NULL)
  {
    // Throw assertion
    return;
  }

  // Do something
}

So now I check every time whether the pointer is NULL and if it is not set to NULL in the first place and not allocated either then that check is useless. So now I am thinking whether I should define my functions like so (although I realize that does not guarantee I get a valid object, at least it won’t be NULL):

void Foo(const somePointer& ptr)
{
  // No need to check anymore, client is responsible

  // Do something
}

And before I do (or don’t, depending on the answers I get here), I thought I would ask here and see what everyone has to say, especially its pros and cons.

Answer 1

Well, if you never ever want a non-existent object passed in, use a reference (Note: non-existent, not non-valid).
If you want that possibility, use a pointer.