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From: Ullrich Koethe (koethe_at_[hidden])
Date: 20010329 16:00:07
Jeremy Siek wrote:
>
> On Thu, 29 Mar 2001, Ullrich Koethe wrote:
>
> koethe> Basic Vector
> koethe>
> koethe> x[i] vector_traits<X>::reference
> koethe>
> koethe> The requirement that basic_vector::operator[] returns an lvalue has
>
> The Basic Vector concept as written does not require an lvalue return
> type.
>
> x[i] vector_traits<X>::reference, which must be a type convertible
> to the value type.
> x[i] = a undefined return type
>
> because nowhere did I say that vector_traits<X>::reference must be an
> lvalue. I just said it needed to be convertible to the value type. If I
> had made it an lvalue, then I wouldn't have needed to require the second
> expression "x[i] = a".
>
Sorry, I was unclear. I meant to say that I want
x[i] = a
replaced with
x.set(i,a)
because this is so much more flexible (with only a minor loss in
readability, e.g.
magnitude.set(i, sqrt(x[i]*x[i] + y[i]*y[i]))
(of course, there are hacks to make x[i] = a work when x[i] is a
computed attribute, but they are really just hacks)
 ________________________________________________________________    Ullrich Koethe Universität Hamburg / University of Hamburg   FB Informatik / Dept. of Computer Science   AB Kognitive Systeme / Cognitive Systems Group     Phone: +49 (0)40 428832573 VogtKoellnStr. 30   Fax: +49 (0)40 428832572 D  22527 Hamburg   Email: u.koethe_at_[hidden] Germany   koethe_at_[hidden]   WWW: http://kogswww.informatik.unihamburg.de/~koethe/  ________________________________________________________________
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