Static kCTFontFeatureSelectorSettingKey 

pub unsafe static kCTFontFeatureSelectorSettingKey: &'static CFString

Available on crate feature CTFont only.

kCTFontFeatureSelectorSettingKey

Key to get or specify the current feature setting.

This key is used with a selector dictionary to get or specify the current setting for the selector. This value is a CFBooleanRef to indicate whether this selector is on or off. If this key is not present, the default setting is used.

See also Apple’s documentation