message: Properly integrate macro variables in doc strings
  See
  for a question-ified description of the problem and the solution.
diff: @@ -266,11 +266,19 @@ impl TransportSender {
  #[macro_export]
  macro_rules! transport_channel_iterator {
  ($ty:ident, $iter:ident, $func:ident) => (
  - /// An iterator over packets of type $ty.
  + transport_channel_iterator!($ty, $iter, $func, stringify!($ty));
  + );
  + ($ty:ident, $iter:ident, $func:ident, $tyname:expr) => (
  + #[doc = "An iterator over packets of type `"]
  + #[doc = $tyname]
  + #[doc = "`."]
  pub struct $iter<'a> {
  tr: &'a mut TransportReceiver
  }
  - /// Return a packet iterator with packets of type $ty for some transport receiver.
  +
  + #[doc = "Return a packet iterator with packets of type `"]
  + #[doc = $tyname]
  + #[doc = "` for some transport receiver."]
  pub fn $func(tr: &mut TransportReceiver) -> $iter {
  $iter {
  tr: tr
  @@ -278,7 +286,9 @@ macro_rules! transport_channel_iterator {
  }
  impl<'a> $iter<'a> {
  - /// Get the next ($ty, IpAddr) pair for the given channel.
  + #[doc = "Get the next (`"]
  + #[doc = $tyname ]
  + #[doc = "`, `IpAddr`) pair for the given channel."]
  pub fn next(&mut self) -> io::Result<($ty, IpAddr)> {
  let mut caddr: pnet_sys::SockAddrStorage = unsafe { mem::zeroed() };
  let res = pnet_sys::recv_from(self.tr.socket.fd,
  @@ -382,7 +392,7 @@ macro_rules! transport_channel_iterator {
  r
  }
  }
  - )
  + );
  }
  transport_channel_iterator!(Ipv4Packet, Ipv4TransportChannelIterator, ipv4_packet_iter);
  