Re: [boost] Big integer library

From: Christoph Ludwig (cludwig_at_[hidden])
Date: 2004-04-30 07:40:00

Hi,

On Fri, Apr 30, 2004 at 12:01:01PM +0200, Richard Peters wrote:
> From: "Christoph Ludwig" <cludwig_at_[hidden]>
> > > There is not much special about my library. Like the gmp, this library
> uses
> > > expression templates to avoid the creation of temporary values, which
> when
> > > the values become large provide an increase in performance.
> >
> > I sometimes wonder whether a bigint library that implements move
> > semantics could not provide an additional significant efficiency
> > gain. (Since I can avoid temporaries most of the time, my applications
> > don't profit from expression templates that much.) I never performed
> > experiments, though, this is only a conjecture.
> >
> > Do you have any plans in this direction?
> 
> What would implementing move semantics look like? Do you mean that an
> expression like x = y * z where y and z aren't used after this expression
> can be implemented as a swap(x, y); x *= z? I'm not sure how to implement
> it, but if a method exists which provides a significant efficiency gain and
> does not interfere with the interface too much, then I'm certainly
> interested in implementing it.

The only proposal I ever toyed with was Andrei Alexandrescu's
Mojo. But recently there were threads about two proposals by David
Abrahams and Andrea Torsello (search the archive for subjects that
contain "move semantics").

AFAIR, no proposal could hide all implementation details from the
user of the classes with move semantics, but the interfaces did not
become too awkward.

Regards

Christoph
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