Function CFSetCreateMutableCopy 

pub unsafe extern "C-unwind" fn CFSetCreateMutableCopy(
    allocator: Option<&CFAllocator>,
    capacity: CFIndex,
    the_set: Option<&CFSet>,
) -> Option<CFRetained<CFMutableSet>>

👎Deprecated: renamed to CFMutableSet::new_copy

Available on crate feature CFSet only.