How to use lifetime in component definition？

[lisiur]

Suppose I have two structures A and B, A contains a tree
, B contains a reference to a node in A. They are all added to the system as resources, how to obtain and modify them in the system function?

Sample code:

struct A(Tree);
struct B(Option<&'static Node>);

fn main() {
    ...
   app.add_resource(A(tree));
   app.add_resouece(B(None));
}

[TheRawMeatball]

I don't think you can use lifetimes for this - all resources and components must be 'static. You should probably make a single 'static struct that wraps the, entire graph and put that in.