CHKPTR Categories

[Mark S. Miller <mark>]

Date: 3 Jul 90 09:20:50
   From: heh <heh@xxxxxxxxxx>

			  Subject:                               Time:9:11
     OFFICE MEMO          CHKPTR Categories                      Date:7/3/90
   Do we really need category objects for CHKPTRs?  Does anyone CAST or otherwise
   test a CHKPTR (and not the contents of the CHKPTR?)  Or are they required for
   stubble to operate properly?
     Why do I ask?  Well, it seems that the MPW linker LOVES to strip these little
   buggers right out of there!  Most other category objects survived just fine...

Hmmm...  I'm surprised the linker is stripping these out.  Each
CHKPTR(FOO)::getCategory() method should have an external reference to
a pointer to the static instance.  I would expect this to cause the
linker to bring them all in.  I don't believe we need these, but we
should remove them iff we make CHKPTRs no longer be Vars.  Does anyone
know of a reason for CHKPTRs to be Vars?

If we make them non-Vars & get rid of all virtual functions (both of
which I think we can do), then they won't need a vtable, and so will
really be approximately as cheap as a naive in-memory pointer.