> I daresay Keith
> could come up with something even better involving templates. :-)
Well, OK, but only because you asked for it:
template <typename T>
inline T* GetObjPtrAs (FormType* f, UInt16 id)
{
return static_cast<T*>(FrmGetObjectPtr (f, FrmGetObjectIndex (f, id)));
}
FieldType* fred = GetObjPtrAs<FieldType> (form, id_EditField);
ControlType* wilma = GetObjPtrAs<ControlType> (form, id_Control);
-- Keith "You, uh, were serious, weren't you, John?"
John Marshall <[EMAIL PROTECTED]> on 11/16/2000 12:14:08 AM
Please respond to "Palm Developer Forum" <[EMAIL PROTECTED]>
Sent by: John Marshall <[EMAIL PROTECTED]>
To: "Palm Developer Forum" <[EMAIL PROTECTED]>
cc: (Keith Rollin/US/PALM)
Subject: Re: SDK prototype question: FrmSetTitle
Ages ago, Ben Combee <[EMAIL PROTECTED]> wrote:
> any chance of a future SDK having FrmGetObjectPtr
> return a "FormObjectType" rather than the current "void *". Effectively its
> just a prototype change, but it would make the intent clearer, and avoid
> ugly C++ casting, since you could use the union member to get at the
> appropriate pointer type.
But it would introduce ugly C casting, since you could no longer use
the implicit conversion in
/* Valid in C only!! */
FieldType *field = FrmGetObjectPtr (form, id_EditField);
Of course C programs could use the union member too, but the point is
that existing C source code which assumed that the implicit conversion
would happen would get broken.
Sorry. No can do.
In my C++ projects, I have a header file with a bunch of functions like
inline FieldType*
GetFieldPtr (FormType* f, UInt16 id) {
return static_cast<FieldType*>(FrmGetObjectPtr (f,
FrmGetObjectIndex (f,id)));
}
This concentrates all the ugly casting in one place. I daresay Keith
could come up with something even better involving templates. :-)
John "still looking at FrmSetTitle"
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