complex_enum_equatable.swift

//
//  Example showing how to add Equatable protocol conformance to a complex enum using a switch statement.
//
//  Useful if you need to compare two enums, e.g:
//    let a = ApplicationViewState.content("foo")
//    let b = ApplicationViewState.connectionError
//    let c = ApplicationViewState.content("foo"
//    a == b  // false
//

enum ApplicationViewState {
    case sync
    case content(String)
    case login
    case connectionError
    case versionError(URL)
}

extension ApplicationViewState: Equatable {
    static func ==(lhs: ApplicationViewState, rhs: ApplicationViewState) -> Bool {
        switch (lhs, rhs) {
            
        case (.sync, .sync):
            return true
            
        case (.content(let lhs), .content(let rhs)):
            return lhs == rhs
            
        case (.login, .login):
            return true
            
        case (.connectionError, .connectionError):
            return true
            
        case (.versionError(let lhs), .versionError(let rhs)):
            return lhs == rhs
            
        default:
            return false
        }
    }
}