A type that provides a collection of all of its values.
- Xcode 10.0+
- Swift Standard Library
Types that conform to the
Case protocol are typically enumerations without associated values. When using a
Case type, you can access a collection of all of the type’s cases by using the type’s
For example, the
Compass enumeration declared in this example conforms to
Case. You access the number of cases and the cases themselves through
Conforming to the CaseIterable Protocol
The compiler can automatically provide an implementation of the
Case requirements for any enumeration without associated values or
@available attributes on its cases. The synthesized
all collection provides the cases in order of their declaration.
You can take advantage of this compiler support when defining your own custom enumeration by declaring conformance to
Case in the enumeration’s original declaration. The
Compass example above demonstrates this automatic implementation.