自作の構造体で Range までは作れたけど、比較に使おうとするとできない…(´・ω・｀)？ #CodePiece

CodePiece.swift

struct MyForwardIndexTypeStruct {
    var num: Int
    init(_ num: Int) {
        self.num = num
    }
}

// Equatable
func == (lhs: MyForwardIndexTypeStruct, rhs: MyForwardIndexTypeStruct) -> Bool {
    return lhs.num == rhs.num
}

extension MyForwardIndexTypeStruct : ForwardIndexType {
    // _Incrementable
    func successor() -> MyForwardIndexTypeStruct {
        return MyForwardIndexTypeStruct(self.num+1)
    }
}

let start = MyForwardIndexTypeStruct(1)
let end = MyForwardIndexTypeStruct(5)
let myRange: Range = start ..< end

let range = 1 ..< 2
switch 1 {
case range:
    print("match") // => "match"
default:
    print("")
}

/*
error: expression pattern of type 'Range<MyForwardIndexTypeStruct>' cannot match values of type 'MyForwardIndexTypeStruct'
case myRange:
*/
switch MyForwardIndexTypeStruct(2) {
case myRange:
    print("match")
default:
    print("")
}