pardo@june.cs.washington.edu (David Keppel) (06/21/88)
I have written a series of routines to implement circular
doubly-linked lists. I want to be able to use these routines to
manipulate several kinds of data structures in one program. I am
having troubles figuring out how to make the appropriate declarations.
The basic structure that the list routines manipulate looks like:
struct q_t {
struct q_t *forward_link, *backwards_link;
int tag;
}
What I want to be able to do is to declare various objects that
have varioius sizes of "other" data in them, so I can say
foo_header_t hdr;
thing = (cast*)malloc( sizeof(foo_t) );
other_thing = (cast*)malloc( sizeof(bar_t) );
enqueue( &hdr, thing, FRONTEND );
enqueue( &hdr, other_thing, FRONTEND );
where "foo_header_t", "thing", and "other_thing" share the common q_t
as the first N bytes but have different things as the rest of the
elements. My problem is that I haven't figured out how to declare
this except as a union type; I don't want to do this because a
"thing", in my case, has only a few bytes of data, while an
"other_thing" has a huge ammount of data.
Can somebody please tell me how to do this correctly? Advance Thanks.
E-mail appreciated. I will summerize if anybody is interested.
;-D on ( I'm lost in a sea of opportunities ) Pardo
pardo@june.cs.washington.edu
{rutgers,cornell,ucsd,ubc-cs,textronix}!uw-beaver!uw-june!pardo