[Boost-users] [units] how to use scaled_base_unit?

Subject: [Boost-users] [units] how to use scaled_base_unit?
From: Olaf Peter (ope-devel_at_[hidden])
Date: 2013-04-23 14:55:17

Hi,

at this time I start to understand boost.units. Following the doc 
http://www.boost.org/doc/libs/1_53_0/doc/html/boost_units/Units.html#boost_unit 
scaled_units are useful. But I didn't found use cases in the test or 
examples. E.g. 
https://svn.boost.org/svn/boost/trunk/libs/units/test/test_output.cpp 
show how to typedef this, but no usage.

I try to map metric/si and imperial/us length to an intrinsic length 
using integer scale factors to avoid double representation uncertainly. 
Using BOOST_UNITS_DEFINE_CONVERSION_FACTOR I can convert meter and inch 
to the intrinsic length. But what about mm/um and thou/mil etc? For this 
I did consider scaled_base_unit. I like to convert between all of them. 
Since the dimensions are constant, no runtime conversation are required 
(as the dollar/euro example it shows). Later area calculations based on 
the intrinsic length are required, convertible also to metric/si and 
imperial systems.

Thanks,
Olaf