Gurus,

   I can't find documentation on this anywhere, though I may be missing
something obvious since I am home-schooled in this sort of C stuff.

   I want to create a struct in C which (in lean form) looks like this:

typedef struct {
     int x,y,h,w;
     void (*paint)(lwin*),              
          (*born) (lwin*),              
          (*die)  (lwin*);              
     int  (*keypressed   )(lwin*,int,int),
          (*clicked      )(lwin*,int,int,int);

   When I compile in gcc I get errors like,

test.c:4: parse error after '*'

   for each time I try to declare an argument as type (lwin *).

   I thought declaring 'struct lwin;' before doing the typedef would fix
it -- it doesn't, nor does using the alternate (c++?) syntax "struct lwin
{.....};".

   I know what I want to do can be achieved in C++ using member
functions, but I don't want to use C++.

   My question is: Can I do this? What is the proper syntax?

   I would appreciate an e-mail cc to twm(a)cmu.edu.

Thank-you!

Tom 7

   typedef struct {
        int x,y,h,w;
        void (*paint)(lwin*),              
             (*born) (lwin*),              
             (*die)  (lwin*);              
        int  (*keypressed   )(lwin*,int,int),
             (*clicked      )(lwin*,int,int,int);
   } lwin;

Fixed:

   typedef struct lwin lwin;
   struct lwin {
        int x,y,h,w;
        void (*paint)(lwin*),              
             (*born) (lwin*),              
             (*die)  (lwin*);              
        int  (*keypressed   )(lwin*,int,int),
             (*clicked      )(lwin*,int,int,int);
   };

There are other possibilities too.
--
(supporter of the campaign for grumpiness where grumpiness is due in c.l.c)

Please: do not email me copies of your posts to comp.lang.c
        do not ask me C questions via email; post them instead

One way of resolving this difficulty is to use the typedef FIRST...

        typedef struct lwin lwin;

        struct lwin {
                int x, y, h, w;
                void (*paint) (lwin *);
        }

or you could do this...

        struct lwin {
                int x, y, h, w;
                void (*paint) (struct LWIN *);
        }

        typedef struct lwin lwin;

You can use the lowercase lwin throughout as well since structure tags
occupy a different namespace from that of typedef's.

--
"I see you have books under your arm, brother. It is indeed a rare pleasure
these days to come across somebody that still reads, brother."

        - Anthony Burgess

--

--
"I see you have books under your arm, brother. It is indeed a rare pleasure
these days to come across somebody that still reads, brother."

        - Anthony Burgess