Promoted the result to `Array`:    ```julia  julia> A + 4  3\xd73 Array{Float64,2}:   5.0   8.0  11.0   6.0   9.0  12.0   7.0  10.0  13.0  ```    The call leads to this line https://github.com/JuliaLang/julia/blob/master/base/broadcast.jl#L37