On 2007-03-19 02:43:36 -0800 Richard Frith-Macdonald <[EMAIL PROTECTED]>
wrote:
On 19 Mar 2007, at 10:24, Michael Gardner wrote:
To use a custom key type with NSMutableDictionary, I defined -hash
and
-isEqual: but not -copyWithZone:, since the NSDictionary docs say
that
keys are retained rather than copied. But when I try to insert a key
of that type, I get an NSInvalidArgumentException saying that my
class
does not recognize -copyWithZone:. If I add that method, the
exception
goes away and everything works fine. I've tried this on both the
latest GNUstep release and on trunk. Are the docs just out-of-date?
Yes, the documentation is just wrong. Dictionary keys do need to be
copied.
I've fixed the documentation (at least, all the errors I spotted) in
svn
trunk to say that keys are copied.
possibly worthwile to explain why things are copied and not retained,
if you add a mutable object to a dictionary and subsequently modify
the object
in a way which modifies the objects -hash value, it would become
inconsistent
with the hash value stored in the dictionary.
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