Custom Optionals in Swift: Implementing Your Own Optional Type

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Swift’s Optional type is a powerful feature that helps us to write safer code by explicitly handling the presence or absence of a value. Swift provides built-in support for Optionals. But what If the libraries or frameworks don't support the syntactic sugar of the (?) for optional?

How can we still implement the core functionality of Optional.

We need to implement our custom Optional type.

The Basics: Defining Our Custom Optional

First, we need to define our custom Optional type using an enum:

enum CustomOptional<Wrapped> {
    case some(Wrapped)
    case none
}

This enum has two cases: some, which contains an associated value of the wrapped type and none, which represents the absence of a value. The generic <Wrapped> allows our CustomOptional to work with any type.

Accessing and Unwrapping Values

Second, let’s add some methods to access and unwrap the values:

extension CustomOptional {
    // MARK: - Accessing and Unwrapping
    var value: Wrapped? {
        switch self {
        case .some(let wrapped):
            return wrapped
        case .none:
            return nil
        }
    }…