addptype(3) create a ptype and add it to a ptype_list

SYNOPSYS

#include "mut.h"
ptype_list *addptype(pthead,type,ptdata)
ptype_list *pthead;
void *ptdata;
long type;

PARAMETERS

pthead
Pointer to a ptype list
type
Flag indicating the pointer owner
ptdata
Generic pointer to any kind of information

DESCRIPTION

addptype creates a new ptype element and adds it to the front of the list pointed to by pthead, and becomes itself the list head.
The ptype_lists are mosty used to create lists of homogeneous elements in mbk, but also for trees, graphs, and so on.
The type argument indicates the pointer type, at the C type meaning, for its owner.
The types allow to access the pointers with adequat cast, and for example to share informations in the USER fields of mbk structures.
The ptdata points to any kind of list or may itself be a value, if proper cast is performed at compilation time, and fills the DATA field of the ptype structure. For details on the structure, see ptype(3).

RETURN VALUE

addptype returns a pointer to the new head of list.

EXAMPLE

#include "mut.h"
#include "mph.h"
void corner(ptfig, name)
phfig_list *ptfig;
char *name;
{
phins_list *i = getphins(ptfig, name);
num_list *ptnum;
phfig_list *model;
   model = getphfig(i->FIGNAME);
   ptnum = addnum((num_list *)NULL, model->X2 - model->X1);
   ptnum = addnum(ptnum, model->Y2 - model->Y1);
   i->USER = addptype(i->USER, (long)PLACEABOX, (void *)ptnum);
}