Re: [boost] units: review

From: Matthias Schabel (boost_at_[hidden])
Date: 2007-03-29 13:27:09

> http://en.wikipedia.org/wiki/International_System_of_Units
>
> The SI rule for pluralising units is that symbols of units are not  
> pluralised[2], for example "25 kg" (not "25 kgs").
>
> Reference 2 is
>
> Bureau International des Poids et Mesures (2006). "The  
> International System of Units (SI)". 8th ed.. Retrieved on 2006-07-14.
>
> So this is quite specific and so I definitely think they should GO  
> for SI units.

Of course, we're not talking about symbols of units (which,  
incidentally, are not pluralized in the library), but full names of  
units. The original rationale was that

quantity<SI::length>	q = 2*meters;

reads a bit better than

quantity<SI::length>	q = 2*meter;

If anything, I would argue that the singular cases are the edge  
cases, since you would only use them for the case of unit valued  
quantities :

quantity<SI::length>	q = 1*meter;

and, by my reading, even this would be better plural :

quantity<SI::length>	q = 1.0*meters;

Naturally, I'm eliding the multiplication in reading this  
expression... Anyway, as with many of these points, I'm not dogmatic.  
I see the merits of simplicity - how about I remove the singular cases?

BTW, Paul, I hope you'll have a chance to give the library a formal  
review. We'd appreciate your input.

Matthias