Why does `1 * String[]` return a Vector{Union{}}?

[Sukera]

Perhaps this topic can help:

Behavior of all() and any() on empty vectors

This caught me by surprise: julia> any(x->true, []) false julia> all(x->true, []) true julia> any(x->false, []) false julia> all(x->false, []) true This seems like a bug - I think that all should never be true when any is false. But I’m guessing there’s a principled reason for this. Can anyone explain it to me?