Le 19/5/2005, "John Carter" <john.carter / tait.co.nz> a ?crit:
>Having asked the question, and heard many replies let me summarise...
>
>On Fri, 6 May 2005, John Carter wrote:
>
>> Imagine a flock of ducks in the sky. Listen.
>> Now remove the ducks. Listen.
>>
>> What is the sound of no duck quacking?
>>
>> What should nil respond_to?
>
>Well, it turned out that there are several sorts of unduck making several
>different unsounds.
>
>There is the uninitialized unduck, which, when you ask it to quack
>says, "You Nana! It was _your_ job to put a duck here and you DID NOT,
>and now you asking it to Quack! Twit!"
>
>Then there is the not applicable duck, which when you ask it to quack
>says, "Sorry, it is just not appropriate nor ever will be appropriate
>to have a duck in _this_ particular instance. Don't even try put a duck
>in here, let alone ask it to quack."
>
>Then there is the no duck, which when asked to quack (or anything else
>for that matter) does nothing, and after having done nothing, leaves
>you with nothing. Which was the only sort of nil I had in my rather
>limited mind when I asked the question.

Goose!

>John Carter 

E

--
template<typename duck>
void quack(duck& d) { d.quack(); }