Re: [boost] Interval Library and comparison operators

From: Victor A. Wagner, Jr. (vawjr_at_[hidden])
Date: 2002-09-07 02:16:32

At Friday 2002/09/06 05:33, you wrote:
>From: "David Bergman" <davidb_at_[hidden]>
> >
> > BUT, the prime reason for keeping the STL convenience implementation of
> > '<=' being '!>' was in order to be "compatible" with STL, according to
> > Herve and Guillaume, in spite of the induced "equivalence" not being an
> > equivalence at all. Thus, I somehow got the idea that it was important.
>
>Having an "STL-compatible" operator< is important if you want to use STL
>algorithms or associative containers with intervals without an explicit
>comparator.
>
>Having operator<= that is !> is important if you want to prevent user
>mistakes, such as replacing
>
>if(!(x < y))
>
>with
>
>if(y >= x)

this isn't equivalent in ANY algebra I'm aware of.
you meant, perhaps:
if(x >= y)

>There is always the option of not defining <= at all.
>
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Victor A. Wagner Jr.      http://rudbek.com
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