Re: [boost] Boost Units library preview

From: Eric Lemings (lemings_at_[hidden])
Date: 2006-08-21 12:43:32

> -----Original Message-----
> From: boost-bounces_at_[hidden] 
> [mailto:boost-bounces_at_[hidden]] On Behalf Of Matthias Troyer
> Sent: Saturday, August 19, 2006 1:55 AM
> To: boost_at_[hidden]
> Subject: Re: [boost] Boost Units library preview
> 
> 
...
> If I understand the above concepts correctly then we only need three
> terms:
> 
> - named unit
> - unnamed unit
> - quantity (value + unit)

I try to keep the definitions as simple as possible.  IMHO, there are
really only four distinct concepts:

dimension - an "abstract" type
quantity - an "abstract" object whose "type" is a dimension
unit - a type "derived" from a particular dimension
measure - an arithmetic object whose "type" is a unit

The last term is a term I introduced to distinguish an object with a
dimension from an object with a unit.  Very important distinction.

Eric.