On 8 Feb 2011, at 15:20, Derrick Brashear wrote: > struct { > int addrtype; > int addrlen; > int addr<> > } rx_addr; > > #define RX_ADDRTYPE_IPV4 1 > #define RX_ADDRTYPE_IPV6 2 Why not just use an opaque? That way you don't get into any of the ordering issues that ints bring with them. struct { int addrtype; opaque addr<>; } rx_addr; Cheers, Simon.