Andy Little wrote:
I don't see why kg as the "SI unit for mass" requires all this prefix_offset stuff. You'd just use pqs::mass:kg, right?
grammes and milligrammes are common units too. The output of socalled coherent quatities is automated so that its not necessary to customise each units ouput. The prefix_offset is necessary to stick the correct prefix on, usually for mass, but also for anything that starts with mass, like 'mass_flow'.
Here's my expectation. Tell me if I'm wrong: pqs::mass:g grams(10); pqs::mass:kg kilograms(10); cout << grams << endl; cout << kilograms << endl; cout << kilograms + grams << endl; I'd expect to see something like this: 10 g 10 kg 10.01 kg How does this involve prefix_offset at all? What's the point of it? How is mass different than, say, length in this regard? If prefix_offset is not exposed to the user at all, then I submit that it serves no useful function in the library and only makes the implementation (and extensions) unnecessarily difficult. -Dave