[boost] Re: physical quantities (was: runtime unit-modifiable ...)

From: Dan W. (danw_at_[hidden])
Date: 2004-01-07 06:42:57

Daniel Frey wrote:
> Illegal AFAIK, you can't define $ portably. Just an idea: 
> unit::make(value)[unit], e.g.:
> unit::speed s = unit::make( 42 )[m/s];
> and possibly the seriously overused _:
> #define _(x) unit::make(x)
> unit::speed s = _( 42 )[m/s];
> and at least _ without ( is not tainted. Maybe possible...

how about...

#define _( expr ) ::boost::spirit::compile_to_cpp( \" expr \" )

_(      s = 2 m/s.      );

..and then train spirit to tell 'm' the unit, from 'm the variable, or 
whatever, from the context  :)  ?

dan