Re: what means the " ' " in use with a record type?

[tmoran@acm.org]

> This is highly misleading, The questioner asked about the apostrophe, and
> Tom is answering about the whole construct.
  I sincerely hope I didn't mislead the questioner.  I thought about
including a mention of the more general subject of qualified expressions,
but, given the rest of the question:
> Has it anything to do with pointers or only in memory writing?
it seemed to me better to give a simple answer to the immediate question.
  I suspect that qualified expressions are fairly rare in practice
except for an allocation with an initial value.

>    x := new (value => x, to => 1);
>
> then the allocator has no idea what you are talking about, since there is
> nothing to say that this is a node. The qualified expression fixes this
  If x is an access to type node, why is the qualified expression needed,
while it's not needed in:
  type fruits is (apple, orange, banana);
  type colors is (red, orange, yellow);
  color : colors;
  fruit : fruits;
begin
  color := orange;
  fruit := orange;