[swift-evolution] Why doesn't removeLast() on Collection return an optional?

Max Moiseev moiseev at apple.com
Tue Oct 18 17:00:57 CDT 2016


Yes, if the author of the collection you’re using performs the check in `removeLast`, but they don’t have to.

> On Oct 18, 2016, at 1:28 PM, Jean-Daniel <dev at xenonium.com> wrote:
> 
> 
>> Le 17 oct. 2016 à 23:20, Max Moiseev via swift-evolution <swift-evolution at swift.org> a écrit :
>> 
>> Hi Louis,
>> 
>> I believe, sometimes there are situations where you know for sure that your collection is not empty. Maybe you are already in the context where the check has been performed. In these cases there is no reason you’d have to pay the price of an emptiness check once again.
> 
> You have to pay the price anyway, as the check has to be performed to decide if the software should abort.
> 
> 



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