pub fn sendmsg_addr<Fd: AsFd>(
    socket: Fd,
    addr: &impl SocketAddrArg,
    iov: &[IoSlice<'_>],
    control: &mut SendAncillaryBuffer<'_, '_, '_>,
    flags: SendFlags,
) -> Result<usize>pub fn sendmsg_addr<Fd: AsFd>(
    socket: Fd,
    addr: &impl SocketAddrArg,
    iov: &[IoSlice<'_>],
    control: &mut SendAncillaryBuffer<'_, '_, '_>,
    flags: SendFlags,
) -> Result<usize>