What is the Never return type?
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.
Available from iOS 8.0 – learn more in my book Pro Swift
Did this solution work for you? Please pass it on!
Other people are reading…
- How to remove duplicate items from an array
- How to specify default values for dictionary keys
- How to add warnings and errors to your code using #warning and #error
- What is an escaping closure?
- What does override mean?
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
