How to get monospaced numbers in UILabel on iOS 9

Question

At WWDC 2015, there was a session about the new “San Francisco” system font in iOS 9. It uses proportional number rendering instead of monospaced numbers by default when lin

Answer 1

Note: The method in the currently accepted answer has started crashing for me in Xcode 7.3 (Swift 2.2), only in Release builds. Eliminating the intermediary monospacedDigitFontDescriptor extension variable fixes the issue.

extension UIFont {
    var monospacedDigitFont: UIFont {
        let fontDescriptorFeatureSettings = [[UIFontFeatureTypeIdentifierKey: kNumberSpacingType, UIFontFeatureSelectorIdentifierKey: kMonospacedNumbersSelector]]
        let fontDescriptorAttributes = [UIFontDescriptorFeatureSettingsAttribute: fontDescriptorFeatureSettings]
        let oldFontDescriptor = fontDescriptor()
        let newFontDescriptor = oldFontDescriptor.fontDescriptorByAddingAttributes(fontDescriptorAttributes)

        return UIFont(descriptor: newFontDescriptor, size: 0)
    }
}