On Sun, Oct 03, 1999 at 10:04:58AM +0200, Norbert Koch wrote: It has. XRECORD_LHEADER returns a lrecord_header * : struct lrecord_header { /* index into lrecord_implementations_table[] */ unsigned type :8; /* 1 if the object is marked during GC. */ unsigned mark :1; /* 1 if the object resides in read-only space */ unsigned c_readonly : 1; /* 1 if the object is readonly from lisp */ unsigned lisp_readonly : 1; /* 1 if the object is a dumped one */ unsigned dumped : 1; /* 1 if the data pointed by the object is dumped */ unsigned data_dumped : 1; }; Let's see... #define XRECORD_LHEADER(a) ((struct lrecord_header *) XPNTR (a)) #define XPNTR(x) ((void *) XPNTRVAL(x)) and in lisp-union.h: # define XPNTRVAL(x) ((x).ui) It, of course, compiles without a problem is you don't une the union type. Looks like I abused the types slightly too much. Oh well, I'll fix that. OG.