Re: Initing sublacss with superclass method

> Am 22.07.2025 um 00:34 schrieb Riccardo Mottola <[email protected]=
t>:
>=20
> =EF=BB=BFHi,
>=20
>=20
> richard wrote:
>> I don't know what OSX does, and having methods of a mutable class (other t=
han -copy...) return immutable instances is unusual/unintuitive, but from a p=
erformance point of view (because character sets can consume a lot of memory=
) it makes complete sense for these methods to return shared/singleton insta=
nces of immutable character sets.
>>=20
>=20
> out of curiosity I checked what apple does on both 10.4 and 10.15
>=20
> In both cases the result is a NSCFCharacterSet
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> Interesting is that during Autocompletion, XCode of 10.4 says it will retu=
rn NSCharacterSet* while 10.15 lies and says it will be NSMutableCharacterSe=
t* !

Come on Riccardo, before accusing Apple of lying, you should better check th=
e facts first. :-)

If you use any of the character set class methods, Xcode says that they retu=
rn a NSCharacterSet *, which is what you=E2=80=99d expect. It=E2=80=98s only=
 when you use them for NSMutableCharacterSet that Xcode says that they retur=
n a NSMutableCharacterSet *. And that is correct as well, as a quick look at=
 either the online documentation for class NSMutableCharacterSet or at the h=
eader NSCharacterSet.h in any recent version of the OS would have revealed: A=
pple simply has chosen to redeclare (and likely reimplement) all of the clas=
s methods In NSMutableCharacterSet to return a NSMutableCharacterSet.

Wolfgang=