Create new types at runtime.swift

enum TypeGenerator {
    private static var last: Chainable.Type = Chain<Void>.self
    private enum Chain<X>: Chainable {
        static func chain() -> Chainable.Type { Chain<Self>.self }
    }
    
    static func next() -> Chainable.Type {
        Self.last = Self.last.chain()
        return Self.last
    }
}

protocol Chainable {
    static func chain() -> Chainable.Type
}