Re: [boost] [Review] Quantitative Units library review begins today March 26

From: Glenn Schrader (gschrad_at_[hidden])
Date: 2007-03-28 14:32:00

Steven Watanabe wrote:
>
> How would you do it?  Using some special set
> of units has problems with extensibility.
> Suppose someone tried to add currency and used
> US dollars as the base and at the same time
> someone else used euros as the base.
>   
Currency is even worse than that. Currency exchange rates fluctuate at 
least daily so the conversion must be table driven so that it can be 
updated. Since this can't be just a compile time conversion it really 
doesn't fit well with the rest of the library. In fact its probably more 
correct to avoid thinking of currencies as a fundamental units since 
both their absolute value (i.e. purchasing power) and relative values 
don't have stable real-world meanings. OTOH, if everybody changed to a 
gold based standard then things might be different but there is probably 
a legion of economists yelling "no way in hell" at their screen right 
about now...

-glenn