Andy Little wrote:
The kilogram rather than the gramme is a base unit in the SI. I think that the history has to do with the emergence of the SI system from the C.G.S system. Presumably they decided that the gramme from the C.G.S system was too small a unit, the mystery then being why C.G.S used centimeters in the first place. Whatever. I agree the whole thing is a logicians nightmare. I'm just the messenger...
But I don't understand why the SI "interface" commands a particular pqs implementation. From the user perspective, they don't really care. But as soon as a programmer tries to extend the framework, nightmares ensue.
I dont think electrotechnology is an extension to the SI. IMO its a different system in which bytes and time exists, but not mass, length, current etc etc.
We're not talking about Mibibytes here. My question is, why does someone extending the "mass" abstract quantity (is that the correct term?) need to worry about prefix_offset? Why isn't "kilo" specified with "3" like it is everywhere else? AFAICT this has no impact on the user interface. The user will just specify pqs::mass::kg and doesn't care what the underlying "prefix number" is. But this change makes the framework extender's job much easier. -Dave