At 6:49 PM -0800 4/1/99, Alex Robinson wrote:
>GCC doesn't like "const RectanglePtr" (or the equivalent, "RecanglePtr
>const") to be used in parameters that actually are given real, const
>data.
Right, that's because "const RectanglePtr" is actualy the same as
"RectangleType * const" -- that is, the pointer is being declared constant,
NOT the thing it points to.
I started to create typedefs like ConstRectanglePtr that expand to
"RectangleType const *" or "const RectangleType *" (they are equivalent),
but I'm starting to think this is a huge waste of time, and what we should
actally be doing is getting rid of RectanglePtr entirely and explicitly
using "const RectangleType *" in the headers.
The only problem with _that_ is many of our types are intended to be
opaque. That is, you should not know the structure of a WindowType, and we
can't make the Win... routines take a "WindowType *" paramater without
exposing WindowType.
We _could_ make the Win... routines take a "void *" or "const void *"
paramater, but then you lose a lot of type checking and will probably have
to do funny casts. ...I suppose we could typedef WindowType to void for
this...
But anyway, that puts us back to having a public "WindowPtr" type that's
passed around as a cookie outside of the OS, and _that_ means we have to
create a "ConstWindowPtr" type for the cases where it's constant. <sigh>
--Bob
