From: Greg Colvin (gcolvin_at_[hidden])
Date: 2000-11-28 22:29:41
From: Lutz Kettner <kettner_at_[hidden]>
> Hi Paul,
> > I agree up to a point. But I take a slightly more extreme view, that there
> > should be no construction from double at all. This is based on my not seeing
> > any use for it, admittedly. Your example seems to indicate that there is a
> > (rare) use for an exact conversion, but in general I feel that it would be
> > surprising more often than useful.
> Yes, there is a good use in geometry, the data comes often in doubles
> (after reading it from a file or so). For example 3d meshes in graphics.
> So I would like to see the (exact) constructor from double, but I can
> also perfectly understand if it will be a cast-like function call.
Why not an explicit constructor?
> With CGAL we like to use LEDA (the library at
> http://www.mpi-sb.mpg.de/LEDA/leda.html, not the language) that has
> good number types. They convert doubles to leda_real and also
> to leda_rational with constructors. I don't know internals though.
> Best regards,
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