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

Subject: Re: [Boost-users] [units] how to use scaled_base_unit?
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2013-04-23 22:55:29

AMDG

On 04/23/2013 11:55 AM, Olaf Peter wrote:
> 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.
> 

scaled_base_unit works exactly like any other
base unit.  For instance, boost::units::si::kilogram_base_unit
is a scaled_base_unit.

> 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.
> 

In Christ,
Steven Watanabe