Eric
You wrote in message news:
[hidden email]...
> I've been experimenting a bit with passing COM null pointers in via
> SDWORD* & DWORD* parameter types and have found that this test seems to
> be wrong.
>
> ExternalInteger | isNull
> "Answer whether the receiver is Null (i.e. equal to 0).
> This message is useful way of testing for NULL pointers or handles."
>
> ^self value == 0
>
>
> The problem is that if the external integer is indeed a null pointer,
> then this will die a mean, nasty horrible death.
>
> A better test, IMHO, would be:
>
> ExternalInteger | isNull
>
> ^self bytes isNull
>
> I believe that this will work more reliably than the other test.
>
> Agree/Disagree?
Up to a point - although it fixes one problem it causes another. In Dolphin
5.0 the implementation is as follows:
isNull
"Answer whether the receiver is Null (i.e. equal to 0).
This message is useful way of testing for NULL pointers or handles."
^super isNull or: [self value == 0]
The superclass definition is (essentially) '^bytes isNull'. This result is
an implementation that answers true if the pointer is null or the value is
null.
Regards
Blair
Locked
