Static kCTFontFeatureSelectorDefaultKey 

pub unsafe static kCTFontFeatureSelectorDefaultKey: &'static CFString

Available on crate feature CTFont only.

kCTFontFeatureSelectorDefaultKey

Key to get the font feature selector default setting value.

This key is used with a selector dictionary to get the default indicator for the selector. This value is a CFBooleanRef which if present and true indicates that this selector is the default setting for the current feature type.

See also Apple’s documentation