Re: [boost] Re: Re: quantity libraries

From: Anatoli Tubman (anatoli_at_[hidden])
Date: 2001-08-14 06:48:26

On Tuesday 14 August 2001 12:27, Kevlin Henney wrote:
> >   From: Anatoli Tubman <anatoli_at_[hidden]>
> >
> >A quantity library that wishes to support both metric
> >and English units must chose one of the following:
> >
> >1. All length are stored in meters.
> >2. All length are stored in feet.
> >3. All length are stored in units specified at configure time.
> >4. Some lengths are stored in feet, others in meters.
> >
> >Every choice has its problems. Choices 1 and 2 are giving unfair
> >preference to users of a particular unit system.
>
> I'm not sure what the problem is. Choosing between 1 and 2 is easy: 1,
> without a shadow of a doubt. The choice in this case is informed by the
> fact that the meter is the more fundamental concept: the foot is
> officially defined in terms of the meter, and can therefore be
> considered something of a derived unit :->

Oh come on. The question is not what is more fundamental, but what is
more useful. Which makes it much trickier, because usefulness is
relative. Meter is also a derived unit. This does not make it
any less useful.

Any *engineering* calculations ought to be in SI, as any engineer
that tried to build a Mars probe will tell you. But not all
calculations are of the engineering kind. 
-- 
anatoli at ptc dot com -- opinions are mine