Cannot broadcast when rand(n) is involved

[giordano]

I think the title is not super clear, but the example below should be:

julia> @. rand(2) + 2.4
ERROR: MethodError: no method matching +(::Array{Float64,1}, ::Float64)
Closest candidates are:
  +(::Any, ::Any, ::Any, ::Any...) at operators.jl:502
  +(::Bool, ::T<:AbstractFloat) where T<:AbstractFloat at bool.jl:112
  +(::Float64, ::Float64) at float.jl:395
  ...
Stacktrace:
 [1] _broadcast_getindex_evalf at ./broadcast.jl:578 [inlined]
 [2] _broadcast_getindex at ./broadcast.jl:551 [inlined]
 [3] getindex at ./broadcast.jl:511 [inlined]
 [4] copy at ./broadcast.jl:763 [inlined]
 [5] materialize(::Base.Broadcast.Broadcasted{Base.Broadcast.DefaultArrayStyle{0},Nothing,typeof(+),Tuple{Base.Broadcast.Broadcasted{Base.Broadcast.DefaultArrayStyle{0},Nothing,typeof(rand),Tuple{Int64}},Float64}}) at ./broadcast.jl:753
 [6] top-level scope at none:0

@chethega pointed out on Slack that this is not surprising by how Meta.@lower works, but I find the error message quite confusing. Also, rand.(2) generates a Vector, as rand(2) does, but rand(2) .+ 2.4 works without problems.

[KristofferC]

Dup of #32338.

As said in that issue, remember that broadcast fuses. You cannot look at rand.(2) on its own.

[giordano]

You cannot look at rand.(2) on its own.

Right. Also the error message makes more sense now, but at first glance it was quite strange. Thanks.