[plt-scheme] Handling passing parameters by reference in foreign.ss

Hi,

I decided to try out foreign.ss, and so I picked Imlib2 API and
created a scheme interface using foreign.ss (which is great, by
the way) for most of the functions now (really nice to see it
works also, eheh) but I'm also having problems with some
function which get parameters by reference like the following:
void imlib_context_get_color(int *red, int *green, int *blue,
int *alpha);

In C it is straightforward to see how it works but I'm having a
hard time on how to create an interface in scheme with
foreign.ss for this function.

Any suggestions would be appreciated.

Cheers,

-- 
Paulo Jorge Matos - pocm at sat inesc-id pt
Web: http://sat.inesc-id.pt/~pocm
Computer and Software Engineering
INESC-ID - SAT Group