[squeak-dev] Re: Newbie Question (about OOPs, maybe) (sorry)

Bert Freudenberg bert at freudenbergs.de
Sat Aug 22 15:06:37 UTC 2009


On 22.08.2009, at 13:15, Adrian Lienhard wrote:

> Oh, don't use asOop. It is useless as an OID as it changes as soon  
> as the GC moves the object in memory... Pointer here really means a  
> C pointer.

Err, did you not read my explanation further up in this thread? This  
is not the case. In Squeak, #asOop is identical to #identityHash. The  
comment is wrong.

> #identityHash has only a size of 12 bits and hence is quite a weak  
> hash and useless for an OID.
>
> In short, the concept of an object ID does not exist (unless, of  
> course, you implement it yourself).

Indeed. I'd also say it's rarely needed, so no big issue.

- Bert -





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