kwikius

> I am sorry to disagree here. No problem :) The discussion here has prompted me to get back to work on my old [physical quantities library](https://github.com/kwikius/pqs/wiki). I may even...

> > Both fps and si use the same `length` base_quantity , so in the above the dimension is length ^ 2 in both fps and si systems isnt it...

I think we are all in agreement that there should be different measurement sytems, but currently everything seems to depend on the si system. On a simpler level, there are...

> > there should be different measurement sytems, but currently everything seems to depend on the si system. > > Well, it is because we chose to implement it that...

If I understand correctly the problem you are referring to, You can use a metafunction (traits class) rather than embed the unit in dimension template parameters. see https://github.com/mpusz/units/issues/187#issuecomment-754138328

I resolved this using 4 concepts (N.B not same semantics if similar named std versions) (These also work with the binary_op metafunction which provides a return type of undefined for...

> Both of the overloads are valid. > > From **mp-units** point of view `std::experimental::math::vector` storing `long double` is just a `Scalar` (not a quantity) and every quantity can be...

We could argue what Scalar means but it doesnt solve your problem ;) Surely this should 'just work' without any WrappedQuantity or other mischief? https://github.com/kwikius/units/blob/kwikius_vector_mul_q/example/linear_algebra.cpp#L269 At least it does work...

> > We could argue what Scalar means but it doesnt solve your problem ;) > > Agree, if you have a better name for the "Scalar" term in a...

> I think I do not fully agree here. > > > since this is not how matrices work with quantities. > > There is more than one way to...