PTYPE(3)						 MBK UTILITY STRUCTURE DEFINITIONS						  PTYPE(3)

NAME

       ptype - mbk list of typed pointers

DESCRIPTION

       The ptype is used to save typed pointers in a list.  The use of this structure is strongly recommanded, when such a need occurs.  It is the
       case in the USER field of all mbk layout and netlist objects, where data specific to different proccessing may  be  accessed  through  this
       unique field. It is the charge of the user to give its pointers a type that will not collide with existing types.

       The declarations needed to work on ptype are available in the header file "/labo/include/mut315.h", where '315' is the actual mbk version.

       The following C structure describes the list of typed pointers :
	      typedef struct ptype {
		 struct ptype	  *NEXT;
		 void		  *DATA;
		 long		  TYPE;
	      } ptype_list;

       NEXT		   Pointer to the next ptype of the list.

       DATA		   Generic pointer that may point where the user wants to.

       TYPE		   Identifier of the user of the pointed data. One shall not access someone else ptype since it doesn't know what's in it.
			   This means also that a ptype user should free the space taken by its datas since it is the only one to know how  to	do
			   it.

       Remark 1:	   a  specialized memory allocator has been built in order to create and free ptype_lists, so absolutly avoid to create or
			   free them an other way than through the access functions.

       Remark 2:	   Now a day, three tools are known to use the USER field of some mbk structures :

			   VTIPARSER	       the parser of vti physical format '.cp' files uses the phcon(3) USER field.

			   LOFIGCHAIN	       the lofigchain function constructs a dual representation of the netlist in the USER  field  of  the
					       losig(3) structure.

			   PLACEABOX	       Genlib's  physical  placement  functions,  in  order to have model sizes in instances.  It uses the
					       phins(3) USER field.

SEE ALSO

       mbk(1), addptype(3), freeptype(3), getptype(3), delptype(3).

BUG REPORT

       This tool is under development at the ASIM department of the LIP6 laboratory.
       We need your feedback to improve documentation and tools.

ASIM
/LIP6							  October 1, 1997							  PTYPE(3)