I believe that in current state PQS can not be accepted to boost. Reasons: 1) It is almost useless for scientists. (of cause, it is very useful for engineers, though). It lacks or makes it really hard to plug-in different systems, such as C.G.S.E. (centimeter, gramme, second, and intensity of electric field from one electron is given by formula: E = e/r^2. Note, no k coefficient, as in SI), standard model in theoretical physics (velocity of light is 1, plank constant is 1, etc.), relativistic model, where only velocity of light is 1 (it means that dimensions of time and length are equal. length is time and time is length). This list can be expanded dramatically (almost every physical problem can benefit from some sort of special dimensions usage). 2) In PQS concept of dimensional analysis is tightly coupled with concept of units. I believe that they _must_ be uncoupled and implemented independently. Dimensional analysis has its own value even without any units at all. I hope that tomorrow I’ll find time to provide more ideas of what Boost.Dimensions and Boost.Units should be to meet my expectations from such a library. Best regards, Oleg Abrosimov.