List order makes types different

[ppiotrow]

The same values in HList (Nominator or Denominator) makes different types if they are present in different order(eg. Kilogram :: Meter is not Meter :: Kilogram)

object Foo {
  import UnitSupport._
  type Momentum = Units[Kilogram :: Meter :: HNil, Second :: HNil]
  object Momentum extends ComplexUnit[Kilogram :: Meter :: HNil, Second :: HNil]

  type MomentumAlias = Units[Meter :: Kilogram :: HNil, Second :: HNil]
  object MomentumAlias extends ComplexUnit[Meter :: Kilogram :: HNil, Second :: HNil]

  val momentum: MomentumAlias = 1.as(Momentum) //will not compile
}