RE: [boost] arithmetic type wrapper

From: Michiel Salters (Michiel.Salters_at_[hidden])
Date: 2001-04-13 06:49:31

> -----Original Message-----
> From: Peter Schmitteckert [mailto:boost_at_[hidden]]
> Sent: Friday, April 13, 2001 12:18 PM
> To: boost_at_[hidden]
> Subject: Re: [boost] arithmetic type wrapper
> 
> Salut,
> 
> > >
> > > meters m = meters (10) + meters (20);  //ok
> > >
> > > feet f = feet (5) + feet (10);  // ok
> > >
> > > meters (10) + feet (20); // oops, compile-time error
> >
> > Wouldn't it be more useful to define conversions between 
> feet and meters?
> >
> And the result type should be ? Living in Europe I would 
> always convert
> to SI units. Maybe it would be better to use explicit 
> conversion then, e.g.
> meters( feet(20) )
> 
> Best wishes,
> Peter

Good point, which just goes to show that meters shouldn't be a type.
meter should be a const length. 

I.e. length L = 10*meter + 2*feet;
float length_in_inches = L / inch;

How class length stores should be undefined.

You still catch
length L =  10*secs; or length()+time();

IOstream behavior probably needs locales etc.

Regards,
Michiel Salters.