Re: extended membership tests

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Dan wrote:
> Here's a fun quiz to test your Ada2012 knowledge, based on an
> observation by Yannick Moy.
>
> Consider this Ada 2012 procedure:
>
> with ada.containers.ordered_sets;
> procedure membership is
>     package int_sets is new ada.containers.ordered_sets(integer);
>     function "="(x,y: integer) return boolean is begin return true;
> end;
>     x: integer := 6;
>     y: integer := 12;
>     b1: boolean := x in y;
>     b2: boolean := x in int_sets.to_set(new_item => y);
> begin
>     null;
> end;
>
> Which of the following are true:
>   a)  b1 is true because 6 <= 12;
>   b)  b1 is true because abs(6) <= abs(12);
>   c)  b1 is true because 12 is an integer multiple of 6;
>   d)  b1 is true because the binary representation of 6 appears in the
> binary representation of 12;
>   e)  b1 is true because x=y is true (using redefined "=");
>   f)   b1 is false because x=y is false (using standard."=");
>   g)  b2 is false because 6 is not in the set containing only the
> number 12;
>   h)  the program is illegal because of b1;
>   i)   the program is illegal because of b2.

Nice quiz... I'll post my answers later, to allow others to think some
more about it... or maybe all interested people should reply to you
privately? would you publish the results later? :)

--
Ludovic Brenta.