c++ - Converting given quantities to different system of base units -

i'm trying use boost-unit 1 of projects. in project several quantities velocity, accelaration, angular velocity represented si-system base units. (m/s, m/s^2, rad/s^2)

the user uses gui interface plot these quantities. let's angular velocity. gui should allow user dynamically change base units, has options:

lengths: m, cm, mm

time: s, ms, min, h

angle: rad, deg

in order use boost-unit project need generic function converting quantity 5*m*s^-2*rad 5*1000/m_pi*180*mm*s^2*deg.

but i'm lost might best approach write function.

i think has like:

template<typename h1, typename h2, typename u, typename v> quantity<v> convert(const quantity<u>& quantity); 

where h1 , h2 of type homogeneous_system, can build make_system.