Re: A class template for an N-dimensional generic resizable array

From: Giovanni Bavestrelli (gibav_at_[hidden])
Date: 2000-12-01 17:01:43

--- In boost_at_[hidden], Kevlin Henney <kevlin_at_c...> wrote:
> In message <906dth+ds3m_at_e...>, William Kempf <sirwillard_at_my-
> deja.com> writes
> >> Where X is an appropriate but short name we haven't yet thought 
of 
> >that
> >> indicates dimension :->
> >
> >Array<int, 3> A3(dim(10) + dim(20) + dim(30));
> 
> I had been hoping to avoid the obvious BASIC reference, but I must
> confess that it has a certain appeal.
> 

This has a certain appeal to me, and at first sight it does not look 
difficult to implement, maintaining the type safety that would make 
it impossible to pass the wrong number of dimensions to the 
constructor. But, keeping the class name you suggested, my approach 
would become:

Array<int, 3> A3(dim(10)(20)(30));

Is it not more concise? Besides, not overloading operator + would 
probably make it less open to abuse. And, using your approach, what 
about:

Array<int, 3> A3((dim(10) + dim(20)) + dim(30));

Should that work? It certainly does not look nice to me. Another 
consideration: we are not adding dimensions, if anything, we are 
multiplying them, so should we overload operator *? All in all, I'm 
not convinced.

> >Or even:
> >
> >Array<int, 3> A3(dim(10), dim(20), dim(30));
> >
> >by overloading the comma operator?
> 

This looks better, but it's still not as concise.

> It would have to be
> 
>         Array<int, 3> A3((dim(10), dim(20), dim(30));
> 

I don't like those extra brackets.

> And even then, I feel a little uncomfortable overloading the comma
> operator in public :-}
> 

I agree.

> Kevlin

Thanks for your ideas!

Giovanni

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