What is the Never return type?
Swift version: 5.1
The Never return type is a special one in Swift, and tells the compiler that execution will never return when this function is called. It’s used by Swift’s fatalError() and preconditionFailure() functions, both of which cause your app to crash if they are called.
The Never return type is useful because it lets Swift waive other requirements. For example, if you’re in a function that must return a value, calling a Never function means you don’t need to return anything – Swift knows you can’t return a value any more.
SAVE 20% ON iOS CONF SG The largest iOS conference in Southeast Asia is back in Singapore for the 5th time in January 2020, now with two days of workshops plus two days of talks on SwiftUI, Combine, GraphQL, and more! Save a massive 20% on your tickets by clicking on this link.
Available from iOS 8.0 – learn more in my book Pro Swift
Similar solutions…
- How to fix “Function declares an opaque return type, but has no return statements in its body from which to infer an underlying type”
- How to fix “Property declares an opaque return type, but has no initializer expression from which to infer an underlying type”
- How to return different view types
- How to ignore return values using @discardableResult
- How to move to the next UITextField when the user presses return
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
