It seems to me that exceptions in libgmp could be handled returning a "decorated" zero value.
Here, for example, the __mp_d field of the mpz_t would contain information about the error (or a no-error value or range of values) when the zero result represents an error case. For backwards compatibility, performance-wise, libgmp would have to be compiled with a flag such as -DZEROERRORS to get this sort of exception treatment. Perhaps there could also be a runtime switch (which defaulted off) for systems like Debian which have diverse requirements. All return results would then need a test for a zero size followed by a test for an error result (perhaps least significant bit in __mp_d being set indicating an error). If someone used this variant of libgmp without adequate checks, they would receive spurious zero results (or possibly a segfault if they dereferenced the __mp_d pointer) for error cases. Note also that any robust system which currently uses libgmp is going to have to have some sort of treatment for errors already -- perhaps with guard conditions before calling libgmp routines. So I do not anticipate too much pain from this approach. Thanks, -- Raul Miller 571/299-7139 _______________________________________________ gmp-devel mailing list gmp-devel@gmplib.org https://gmplib.org/mailman/listinfo/gmp-devel
