How can I use the fromRaw() function of enum

Question

I create a enum like the following and I try to use the fromRaw() function.

enum Test : Int {
    case a = 1
    case b, c
    func description() -> String{
        switch self {
        case .a:
            return "a"
        default:
            return String(self.toRaw())
        }
    }
}

It works in the situation I use like this. The bvalue.description() gives me the result "2".

if let bvalue = Test.fromRaw(2) {
    bvalue.description()
}

But when I try to use it without If statement, like the following. It gives me a wrong notification on the second line said "Invalid use of '()' to call a value of a non-function type String."

let bvalue = Test.fromRaw(2)
bvalue.description()

I was confused. What is the difference within If or without If statement? Why the second way cannot work? What type is this fromRaw() function returned?

Answer 1

Note that fromRaw() no longer exists. The new usage would be:

Test(rawValue: 2)