>> the C standard explicitly allows a pointer to a structure type to be >> converted to the type of its first member and back, to another >> structure type and back, or to char * or void * and back, > I rather doubt that you can convert to a different structure type and > back.
I feel sure Dennis Ferguson meant "to _a pointer to_ a different structure type" there. As I read it, the anti-alias rule doesn't actually say anything about the pointers themselves, only about what results when you follow them; if the code never followed the pointers, it could compare them just fine without risk (though I'm going to ask my go-to C reference person to check my reading on this point). /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mo...@rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B