I realize now I may have been misunderstanding http://docs.julialang.org/en/release-0.4/manual/performance-tips/#avoid-containers-with-abstract-type-parameters for a long time... Is the recommendation there only related to parameterized types, or any user defined type? My specific question, in the latter case, is the following
Since Function is an abstract type after https://github.com/JuliaLang/julia/pull/13412#issuecomment-175200009 what is the recommended way to have e.g. immutable J a::Function b::Function end be used in a performant way? Evidently, we should not form e.g. an Array{Function, 1}, but would using types like this in code give similarly poor performance? Thanks, Max
