Re: [Boost-users] boost::units - converting from one derived_dimension to another across systems (imperial to metric)

Subject: Re: [Boost-users] boost::units - converting from one derived_dimension to another across systems (imperial to metric)
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2018-11-15 15:18:44

AMDG

On 11/14/2018 05:04 AM, Matt Vinson via Boost-users wrote:
> I am having trouble converting from one derived_dimension to another across systems (imperial to metric).  I'd like to convert, say, lb/in to, say, kg/m.  I thought I would do the following but get a compiler error #:

It's not going to work.  lb is a unit of
force, but kg is a unit of mass.  They are not
compatible and there is no conversion between
them.

> *.h--------------------------------------------------------------------------------
> namespace dimensional_analysis {
> Â Â  Â namespace lineal_force {Â Â  Â Â Â Â  //lb/in
> Â Â  Â Â Â  Â typedef boost::units::derived_dimension<
> Â Â  Â Â Â  Â Â Â  Â boost::units::us::pound_force_base_unit, 1,
> Â Â  Â Â Â  Â Â Â  Â boost::units::us::inch_base_unit, -1
> Â Â  Â Â Â  Â >::type lb_per_inch_dimension;

units are not dimensions.  You can't use
derived_dimension with base_units.

> Â <snip>
> 

In Christ,
Steven Watanabe