Function life in Rust

Question

So, I'm trying to compress callbacks to this enumeration ( Visual) option - which will be saved in a vector, as shown inside a struct EntityComponents:

enum Component {
    Position([f64; 2]),
    Visual(& Fn(Entity) -> ()),
}

struct EntityComponents {
    components_of_entity: HashMap<TypeId, Vec<Component>>,
}

However, Rust requires me to provide explicit lifetime parameters here. My idea is that I want the function reference to be at least as long as its argument ( Entity), but I don't know what the syntax for this will look like? Is it possible?

The idea is that as long as it Entityhas a component Visual, we can use this callback to display it!

Answer 1

Few things:

• fn() &Fn(). Fn, ol. ( , ), , - .
  • , , , , Box<Fn()>, .
  • , , Visual(fn(Entity)),. . , .
  • , Fn, - ? , :
  • Entity: .
  • - : <'a>
• Fn(Entity) -> (). -> () , .