This is the kind of thing that would be pretty straight-forward in Julia, I imagine. Independent libraries for uncertainties and units could easily be remixed together if the unitful quantity accepts any number type, and the uncertainties just define a new number type. Multiple dispatch should generate consistent downstream behavior "for free".

Indeed:

    julia> using Unitful: m, s

    julia> using Measurements

    julia> Δx = (3.0 ± 0.1)m
    3.0 ± 0.1 m

    julia> t = (1.0 ± 0.2)s
    1.0 ± 0.2 s

    julia> v = Δx / t
    3.0 ± 0.61 m s^-1