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From: stanley@West.Sun.COM (Stanley Friesen [Contractor])
Subject: Re: nested functions
Date: 1999/06/16
Message-ID: <7k610k$pp7@abyss.West.Sun.COM>#1/1
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Approved: Fergus Henderson <fjh@cs.mu.oz.au>
References: <7jd4c5$nup$1@nnrp1.deja.com> <7jrv0r$dfq$1@engnews1.eng.sun.com> <081650426190c69CPIMSSMTPU07@email.msn.com> <3763A8D5.9786D8C2@wizard.net>
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In article <3763A8D5.9786D8C2@wizard.net>,
James Kuyper  <kuyper@wizard.net> wrote:
>
>Just because a function is being called outside the parent's scope
>doesn't mean that the parent's scope has ended.

I guess the problem here is an ambiguity in the phrase "outside of the
parent's scope".  Once can interpret being in a function called by the
the parent function as still being "in" the parent's scope in some sense.

> In fact, that's exactly
>the case in one of the examples you gave:
>
>> void Container::DoSomethingToAll(/* function parameters */)
>> {
>>   // local variables
>>   void DoSomethingToOne(T& t) { /* use t, local variables and function
>> parameters */ }
>>   ForEach(DoSomethingToOne);
>> }
>
>Therefore, the question of whether it's possible/desirable to allow
>local function pointers to exist and be interchangable with global
>function pointers is very relevant.

Well, based solely on this example I do not see why ForEach needs to be
declared to take a generic function pointer.  It could easily be declared
to take a nested function pointer.  Or it could, even better, be declared
as a template. (To be general it needs to be a template anyhow, since
function pointers with different signatures are not interchangeable as it
is, so nothing is lost by doing so).
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