Generic class that conforms to Comparable in Swift

Question

I\'m attempting to create a simple generic node class that conforms to the Comparable protocol so that I can easily compare nodes without accessing their key. When I attempt

Answer 1

You're close! The Node class already specifies that for Node, D must conform to Comparable. Therefore, Node in the decl for == and < is redundant. Instead, you want to restrict the types that the operators can be invoked upon:

func < (lhs: Node, rhs: Node) -> Bool {
    return lhs.key < rhs.key
}


func == (lhs: Node, rhs: Node) -> Bool {
    return lhs.key == rhs.key
}

class Node: Comparable {

    var key: D!
    var next: Node?
    var prev: Node?

    init(key: D) {
        self.key = key
    }
}