If you use ObjC APIs that have optionals for both value and error in their callback handlers, this extension to map them into a Result type might be useful.
Use first(where:) to get the first element of the sequence that satisfies the given predicate.
Use tuples to sort Comparable objects based on multiple properties. Example: sorting contacts by surname; then by name, to see all names from the same family in a row.
Use Swift's property observers to observe and respond to changes in a property’s value. Both `willSet` and `didSet` takes a default parameter to get new and old values
Use a generic type in type aliases to increase code reusability. Notice how the same type alias is used for all Post, [Post], and [Book] 😎
Use the ~= operator in Swift to check for patterns. Say you have an array and you want to get an object at index in a safe way