floating point - Enforcing rational-based conversions between custom-unit-based quantities in Boost.Units -

floating point - Enforcing rational-based conversions between custom-unit-based quantities in Boost.Units -

i have custom unit scheme defined, derives boost::units::si::time. kid units defined using boost::units::make_scaled_unit, hence conversion factors specified using boost::units::scale , boost::units::static_rational, e.g. boost::units::scale<1020, boost::units::static_rational<1> >.

in general not complain, if wasn't boost::units::scale::value_type beingness 'double'. result runtime conversions between quantities involve floating point arithmetics, whereas ratios between custom units integers, e.g. 1 apple equals 18 oranges, , conversions using rational-based factors suffice.

is there way override floating point arithmetics used units convesion else? thanks.

edit: 1. quantities defined using integer types.

floating-point data-conversion rational-numbers boost-units