GCArray copies

[Markus Hitter]

Hello

While trying to get GNUstep to compile on Mac OS X 10.1.5 I came across 
a detail in GC(Mutable)Array's implementation I can't explain myself.

Both (GCArray's and GCMutableArray's) implementations of 
-mutableCopyWithZone: use:

    return [[GCMutableArray allocWithZone:zone initWithArray:self 
copyItems:NO];

All the objects in the copied array get a retain.

Both immutable copies (-copyWithZone:) are implemented as:

    return [[GCArray allocWithZone:zone initWithArray:self 
copyItems:YES];

All the objects in the copied array are actually duplicated.


I just fail to see why it makes a difference wether the resulting array 
is mutable or not. Doing deep copies has the potential to waste memory, 
of course.

Lurking around in all other NSArray and GCArray methods, doing any 
creation, expansion or whatever with arrays, the handled objects always 
get a retain, only.


With the current implementation,

    [(GCArray *)self copyWithZone:0];
and
    [[GCArray alloc] initWithArray:self];

gives two different results, surprisingly the later one uses less 
memory.



Any insight?


Thanks,
Markus

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Dipl. Ing. Markus Hitter
http://www.jump-ing.de/