[boost] Re: physical-quantities (automatic conversions)

From: Dan W. (danw_at_[hidden])
Date: 2004-01-09 17:13:37

Matthias Schabel wrote:
> Consider :
> 
> x meters + (y planck_length - z centimeters) ->
> 
> furlongs z = proxy<op<plus,meters,op<minus,planck_length,centimeters> >
> 
> Do we convert y and z to meters, x and z to planck_lengths, or x and y  
> to centimeters before
> the arithmetic and conversion to furlongs?  The outcomes can be  
> different, as has been discussed earlier, due to precision issues.

Exactly! I'd rather be forced to write a long expression one op at a 
time, writing partial results to named variables, using explicit 
conversions, each on a new line. It's more clear, and much easier to debug.