Function CFStringCreateMutableCopy 

pub extern "C-unwind" fn CFStringCreateMutableCopy(
    alloc: Option<&CFAllocator>,
    max_length: CFIndex,
    the_string: Option<&CFString>,
) -> Option<CFRetained<CFMutableString>>

👎Deprecated: renamed to CFMutableString::new_copy

Available on crate feature CFString only.