#swift equatable example for #medium

equatable.swift

class Cheese: Equatable {
    static func == (lhs: Cheese, rhs: Cheese) -> Bool {
        return lhs.rating == rhs.rating
    }
    let rating : Int
    init(rating: Int) {
        self.rating = rating
    }
}
/// ...
cheeses.contains(c1) // true