Subscript a dictionary with an enum having a matching rawValue type without having to use .rawValue after the case

Dictionary+EnumSubscript.swift

extension Dictionary {
    subscript<T: RawRepresentable>(_ key: T) -> Value? where T.RawValue == Key {
        return self[key.rawValue]
    }
}

// Usage:
enum Type: Int {
    case easy
}

enum Key: String {
    case label
}

let types = [0: "🎉"]
types[Type.easy] // "🎉"

let info = ["label": "💥"]
info[Key.label] // "💥"