Re: [boost] Re: Quantity libraries: SIunits

From: Dean Foster (foster_at_[hidden])
Date: 2001-09-15 14:38:27

> From: eford_at_[hidden]
>
> So I'd say something like 
>   typedef enum { sugar = 100, flour = 101 } ingredients;
>   typedef unit_unconvertible<teaspoon, ingredients::sugar>
> teaspoon_of_sugar; 
>   typedef unit_unconvertible<tablespoon, ingredients::sugar>
> tablespoon_of_sugar;
>   typedef unit_unconvertible<cup, ingredients::flour> cup_of_flour;
> 
> Then conversions between different "of sugar" units would be
> automatic, but conversions between any unit of sugar and any unit of
> flour would generate compile time errors.
> 

I think you hit the nail on the head here.  There are two very
different concepts: how you measure something, and what is being
measured.  Often times what is being measured is the more important
detail.  I want to be able to have a signature of a function that
identifies which arguments are sugar and which are flour.  So this
double templating might sort out this distinction.

dean

=============================================================================
Dean Foster                                                   dean_at_[hidden]
Statistics, Wharton, U. Penn                                     215 898 8233
Philadelphia PA 19104-6302                 http://diskworld.wharton.upenn.edu