Function CMMetadataCreateKeySpaceFromIdentifier 

pub unsafe extern "C-unwind" fn CMMetadataCreateKeySpaceFromIdentifier(
    allocator: Option<&CFAllocator>,
    identifier: &CFString,
    key_space_out: NonNull<*const CFString>,
) -> i32

Available on crate feature CMMetadata only.

Creates a copy of the key value that was encoded in the identifier as CFData.

Safety

key_space_out must be a valid pointer.