Re: [boost] [xint] Third release is ready, requesting preliminary review

Subject: Re: [boost] [xint] Third release is ready, requesting preliminary review
From: Stewart, Robert (Robert.Stewart_at_[hidden])
Date: 2010-05-03 11:48:55

DE wrote:
>  Stewart, Robert wrote :
> > Chad Nelson wrote:
> >> If I read your example correctly, then that's about what I
> >> was thinking
> >> of: algorithms that have to start with a copy of one or more of the
> >> passed-in parameters, but then need to modify it/them. The division
> >> algorithm requires this, just as one example off the top
> >> of my head.
>
> > If your algorithm requires a copy, then COW should make it slower
> > because it will first manipulate the reference count and because you
> > must query in each mutating operation whether to make a unique copy.
>
> i believe that mutating operations are so expensive that the cow
> overhead becomes negligible
> and one can live with it unless he is very pedantic

Once again, allow me to point out that the copy was being made in order to mutate the copy.  The COW operations are superfluous in that case.

_____
Rob Stewart                           robert.stewart_at_[hidden]
Software Engineer, Core Software      using std::disclaimer;
Susquehanna International Group, LLP  http://www.sig.com

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