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From: Joshua Cranmer <Pidgeot18@verizon.invalid>
Newsgroups: comp.lang.java.programmer
Subject: Re: setSize ArrayList, when will it come?
Date: Wed, 10 Aug 2011 18:16:57 -0500
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On 8/10/2011 2:04 AM, Jan Burse wrote:
> Joshua Cranmer schrieb:
>> Or you could use addAll and Collections.nCopies to implement setSize,
>> and use ListIterator to do reverse iteration.
>
> No you didn't get it. I need a fast specialized
> setSize() as argued in the bug reference. According
> to the collections documentation, the nCopies method
> does create an extra object:
>
> http://download.oracle.com/javase/1.4.2/docs/api/java/util/Collections.html#nCopies%28int,%20java.lang.Object%29
>
> ... The newly allocated data object is tiny (it contains
> a single reference to the data object). ...
>
> But it is not only that this tiny object of type
> Collections.CopiesList will be created. For addAll
> call an Iterator AbstractList.Itr will be
> created I guess, not sure.

Okay, if you're so annoyed about the creation of several objects, you 
can create your own version of a CopiesList that implements both 
Collection and Iterator and implements everything on itself, for a 
single overhead of around 12 bytes. If that is still too much, run a 
garbage collection. You now have a few hundred extra kilobytes of data. 
If you're still complaining, you're using the wrong language.

-- 
Beware of bugs in the above code; I have only proved it correct, not 
tried it. -- Donald E. Knuth