Function zvariant::to_writer_fds

pub fn to_writer_fds<B, W, T: ?Sized>(
    writer: &mut W, 
    ctxt: EncodingContext<B>, 
    value: &T
) -> Result<(usize, Vec<RawFd>)> where
    B: ByteOrder,
    W: Write + Seek,
    T: Serialize + Type, 

Serialize T that (potentially) contains FDs, to the given writer.

This function returns the number of bytes written to the given writer and the file descriptor vector, which needs to be transferred via an out-of-band platform specific mechanism.