Using a captured variable in a closure makes it somehow a Core.box.
Generator defines an anonymous with maxV so it is hitting something like
this https://github.com/JuliaLang/julia/issues/15276
Smaller repro
function c!{T}(::T,P)
if length(P)>2
maxV = one(T)
d = x->maxV
end
P
end
On Friday, September 9, 2016 at 1:02:29 PM UTC+3, Patrick Kofod Mogensen
wrote:
>
> So, I am kind of confused here. In my code, a maxV = maximum(V) is labeled
> as Core.Box in @code_warntype, but if I remove a line after the line where
> maxV is calculated, it is correctly labelled as eltype(V). Can anyone
> explain what happens/what I am doing wrong here? This is not the whole
> function, I've tried to remove all irrelevant code.
> V = [0.,]
> P = Vector{Float64}[[0.0,], [0.0,]]
> U = Vector{Float64}[[1.,], [1.,]]
> F = Matrix{Float64}[eye(1), eye(1)]
> b = 0.9
>
> function c!{T}(P, U, b::T, F, V)
> if length(P) > 2
> maxV = maximum(V)
> d = sum(exp(U[ia]+b*F[ia]*V-maxV) for ia = 1:length(P))::T
> end
> P
> end
>
> # This shows maxV as Core.Box
> @code_warntype c!(P, U, β, F, V)
>
>
> function c!{T}(P, U, b::T, F, V)
> if length(P) > 2
> maxV = maximum(V)
> end
> P
> end
>
> # This does not show maxV as Core.Box, but as eltype(V) as I expected
> @code_warntype c!(P, U, β, F, V)
>
> Thanks
>
