Articles, podcasts and news about Swift development, by John Sundell.

Nested generic types

Published on 10 Apr 2018
Basics article available: Generics

Types that are nested in generics automatically inherit their parent's generic types - which is super useful when defining accessory types (for things like states or outcomes).

struct Task<Input, Output> {
    typealias Closure = (Input) throws -> Output

    let closure: Closure
}

extension Task {
    enum Result {
        case success(Output)
        case failure(Error)
    }
}

Support Swift by Sundell by checking out this sponsor:

Raycast

Raycast: Take the macOS Spotlight experience to the next level: Create Jira issues, manage GitHub pull requests and control other tools with a few keystrokes. Easily automate every-day tasks and boost your developer productivity by downloading Raycast for free.