On 2013-12-11 11:42:25 +0100, Florian Pflug wrote: > On Dec5, 2013, at 15:44 , Andres Freund <and...@2ndquadrant.com> wrote: > > There might be some ugly compiler dependent magic we could do. Depending > > on how we decide to declare offsets. Like (very, very roughly) > > > > #define relptr(type, struct_name, varname) union struct_name##_##varname{ \ > > type relptr_type; \ > > Offset relptr_off; > > } > > > > And then, for accessing have: > > #define relptr_access(seg, off) \ > > typeof(off.relptr_type)* (((char *)seg->base_address) + off.relptr_off) > > > > But boy, that's ugly. > > Well, uglyness we can live with, especially if it's less ugly than the > alternatives. But I'm afraid is also unportable - typeof() is a GCC > extension, not a part of ANSI C, no?
Yes (although there's C11 stuff to do equivalent stuff afair) - I was thinking of only doing it for compilers we support that dark magic for and fall back to returning a void* for the others. We'll probably miss a cast or two required on !gcc that way, but it's still likely to be less error prone. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers