Re: [boost] [units]

From: Matthias Schabel (boost_at_[hidden])
Date: 2007-03-05 16:36:56

>>   a) It might be handy, though, to have (for example) a log function
>>   that enforces unitless quantities.  For example,
>>
>>      log ( velocity * time / meters )
>>
>>   is fine, but if you forget to multiply by the time, you get a
>>   helpful error message.

Cases where the function argument reduces to a dimensionless quantity
already all work because dimensionless quantities can be implicitly
converted to their value type :

std::cout << std::sqrt(quantity<SI::velocity> 
(9.0*SI::meters_per_second)*SI::seconds/SI::meters) << std::endl;

gives

3

>>   b) It might also be handy, if possible, to have some functions that
>>   take units and know what to do; for example, sqrt (m*m) properly
>>   returns meters, and so forth.

True - we can support integral and rational powers, but not irrational
ones...

Matthias