AMDG Thomas Taylor wrote:

Is there an easy way to check if two quantities have the same dimension?

E. g. a user enters a weight in tons and asks for a conversion to kilograms. So now at run time I would like to know if tons and kilograms have the same dimensions (i. e. are convertable) or not (illegal conversion).

Each unit has a nested dimension_type typedef. Use it with boost::is_same. In Christ, Steven Watanabe