Undo changes of 3560f54e3eb3 and change to result a little bit to avoid allocations. Trying different signatres reveals some strange interactions with julias dispatch: allocate: getrange(gridsize::Integer, closuresize::Integer, region::Type{<:Region}) no allocate: getrange(gridsize::Integer, closuresize::Integer, region::R) where R allocate: getrange(gridsize::Integer, closuresize::Integer, region::R) where R <: Type{<:Region} no allocate: getrange(gridsize::Integer, closuresize::Integer, region::DataType)

g = sbp.Grid.EquidistantGrid((200,), (0.0,), (2pi,))
op =sbp.readOperator("d2_4th.txt","h_4th.txt")
Laplace = sbp.Laplace(g,1.0,op)

init(x) = cos(x)
v = sbp.Grid.evalOn(g,init)
u = zeros(length(v))

sbp.apply!(Laplace,u,v)

@show u
sbp.Grid.plotgridfunction(g,u)