Re: Obj-C question: protocol usage and inheritance
Re: Obj-C question: protocol usage and inheritance
- Subject: Re: Obj-C question: protocol usage and inheritance
- From: Nat! <email@hidden>
- Date: Tue, 17 Sep 2002 23:44:15 +0200
Am Dienstag, 17.09.02 um 06:06 Uhr schrieb Nicola Pero:
On Mon, 16 Sep 2002, Normand Rivard wrote:
According to
http://www.toodarkpark.org/computers/objc/moreobjc.html#787
(look for "Conforming to a Protocol"), "A class is said to conform to
a
formal protocol if it adopts the protocol or inherits from a class
that
adopts it. " This could mean that MySuperClass should also conform to
the protocol MyClassType to shut up the warnings. The problem is that
in
general, it doesn't make sense (although it might in my specific
case).
If someone from Apple from the compiler group can reply to this, I
would
appreciate. My opinion is that a class should be said to conform to a
formal protocol if it adopts the protocol **by implementation or
inheritance** or inherits from a class that adopts it. I don't think
it
would break any existing code if the compiler could be changed
(fixed?)
to support that definition. Did I mention that even if I have
warnings,
this code works perfectly well at run time?
Please read the documentation for the -Wno-protocol compiler switch.
But is it too much to ask from the compiler to look whether the
"missing method" is declared in the superclass(es) before issueing the
warning ? Although the compiler can not determine that such a method
does not exist, the programmer can tell the compiler in the header of
the superclass that such a method is supposed exist. That's what
headers are for. Otherwise if the method is really not anywhere
declared a warning can indeed by very helpful! Turning it off is not
the optimal solution.
I suspect that fixing the compiler warning is fairly simple, as all the
information (class hierarchy, implemented methods) should be available
at compile time. (No I don't want to fix it :))
Nat!
Jedenfalls sind zehn Fehlstarts hintereinander [E. Fuchs]
ein sehr interessanter Beweis
fuer unsere Theorie
von der natuerlichen Ueberlegenheit des Dezimalsystems
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