Struct with array of pointers to other structs of the same type as field

General Usage
1

Newbie question: I would like to implement lattice structure as an array of structs named Node, where each Node contains as one of its field a list of its neighbouring Nodes in the lattice. My, possibly naive, first try

mutable struct Node
    value :: Int
    neighbors :: Array{Union{Node,Int},1}
end

where I use the Union type to duck the issue of self-reference works, but I wonder if there is a more elegant way, and if there are no performance penalties incurred by using the Union type in this way.

2

A struct can reference itself no problem:

mutable struct Node
    value :: Int
    neighbors :: Array{Node,1}
end
3

Thanks, I was apparently misled by some earlier post that suggested otherwise.

4

I think it was was not always possible, I remember having problems with self-referencing structures more than a single time in the last years. But it may be that the problem only arises if the structure is directly in a field, not wrapped inside another container.