Swift 3: Expression implicitly coerced from 'UIView?' to Any

Question

Someone else must have received this message while (or after) converting an iOS project to Swift 3, yet when I do a Google search, I get no relevant results.

Anyway,

Answer 1

This will happen when the function you are calling has a parameter of type Any, and you are passing an optional.

For example:

let color: UIColor? = UIColor.red
UIBarButtonItem.appearance().setTitleTextAttributes([NSFontAttributeName: color], for: .normal)

Notice that color is of type UIColor? and that setTitleTextAttributes expects a dictionary of type [String: Any]?.

In order to avoid the warning you have to either force unwrap your optional, or cast it to Any.

UIBarButtonItem.appearance().setTitleTextAttributes([NSFontAttributeName: color!], for: .normal)

or

UIBarButtonItem.appearance().setTitleTextAttributes([NSFontAttributeName: color as Any], for: .normal)