Function CTFontDescriptorCreateCopyWithVariation 

pub unsafe extern "C-unwind" fn CTFontDescriptorCreateCopyWithVariation(
    original: &CTFontDescriptor,
    variation_identifier: &CFNumber,
    variation_value: CGFloat,
) -> CFRetained<CTFontDescriptor>

👎Deprecated: renamed to CTFontDescriptor::copy_with_variation

Available on crate feature CTFontDescriptor only.