implement optional with enum in swift

You can use optional enums in Swift to represent values that may or may not be present in your code. Here's an example of how you can implement this:

main.swift
enum OptionalValue<T> {
   case none
   case some(T)
}

let possibleValue: OptionalValue<Int> = .some(100)
let emptyValue: OptionalValue<Int> = .none

switch possibleValue {
case .some(let value):
    print("The value is \(value)")
case .none:
    print("The value is nil")
}

switch emptyValue {
case .some(let value):
    print("The value is \(value)")
case .none:
    print("The value is nil")
}
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In this code, we've defined an enum called OptionalValue that has two cases: .none and .some. The .none case represents the absence of a value, while the .some case stores an actual value of the generic type T.

We've then created two instances of this enum, one with a value of 100 and one with no value at all. We can then use a switch statement to check which case is being used for each instance of the enum.

By using a generic type in the OptionalValue enum, we can use this implementation for any type, whether it's an integer, a string, or a custom object.