Labelled Array Constructors do not promote to dual numbers

[ChrisRackauckas]

julia> using ForwardDiff, LabelledArrays

julia> SLVector(a=2.0,b=ForwardDiff.Dual(1,2))
2-element SLArray{Tuple{2},Real,1,2,(:a, :b)}:
                  2.0
 Dual{Nothing}(1,2)

[ChrisRackauckas]

These should be using promote_type instead of just convert(T:

https://github.com/JuliaDiffEq/LabelledArrays.jl/blob/master/src/slarray.jl#L1-L19

[andreasnoack]

So this is actually an issue in StaticArrays, see JuliaArrays/StaticArrays.jl#670, caused by generated functions.