Re: C Integers -> Booleans: shortcut?

["Randy Brukardt" <randy@rrsoftware.com>]

"Simon Wright" <simon@pushface.org> wrote in message
news:x7vpthkrg0h.fsf@smaug.pushface.org...
> chris <spamoff.danx@ntlworld.com> writes:
>
> > Can you (in general) import a function taking/returning a C integer
> > and treat it like a boolean for import?  Let the compiler deal with
> > the difference?
>
> With GNAT you would say
>
>   type C_Boolean is new Boolean;
>   pragma Convention (C, C_Boolean);
>
> with the meaning that 0 => False, anything else => True.
>
> For other compilers I would think you'd be better off specifying
> Interfaces.C.int and comparing to 0.

Janus/Ada automatically converts Boolean to the C equivalent for calls. We
used it in our early Windows bindings - made things quite a bit clearer.

But the point is that it isn't standard, so if you want your code to work on
other compilers, don't do that. Claw doesn't use that, for instance.

                   Randy.