On 18/10/2018 22:17, Peter Eisentraut wrote: > On 17/10/2018 23:51, Andres Freund wrote: >>> __builtin_types_compatible_p(const char *, char *) returns false (0) for me. >> >> Right, that's why I added a const, inside the macro, to the type >> specified in the unconstify argument. So typeof() yields a const char *, >> and the return type is specified as char *, and adding a const in the >> argument also yields a const char *. > > Yeah, that works. The C++-inspired version also allowed casting from > not-const to const, which we don't really need.
> Attached is my previous patch adapted to your macro. Oh, I forgot to mention, your version doesn't work for this code in pqexpbuffer.c: str->data = (char *) oom_buffer; That's probably not a big deal though. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services