Re: Ada Interfaces and the Liskov Substitution Principle

[Maciej Sobczak <see.my.homepage@gmail.com>]

On 6 Cze, 16:46, Maciej Sobczak <see.my.homep...@gmail.com> wrote:

> > My congratulations! But that's not all:
>
> > procedure Swap (X, Y : in out Integer);
>
> > declare
> >    X : Positive := 1;
> >    Y : Integer := -1;
> > begin
> >    Swap (X, Y);
> >     -- oops
>
> Yes, let's ban it too. Inout parameters should match exactly in terms
> of constraints (see below).

Here I was confused by something different. This subject is unrelated
to assignment.

If we want class-wide types to behave in all aspects like
unconstrained types (or like constrained types that can have
additional constraints added), then indeed this example shows serious
problem with my reasoning.

I will come back to this in a while.

--
Maciej Sobczak
http://www.msobczak.com/