Due to a change in glibc, an identical binary compiled with g++ 4.3 and run on different systems prints a different result for nan. In the program at the end of the report, a x86_64 binary run on an Ubuntu 10.04.1 LTS prints "-nan" while the same exact binary run on Ubuntu 8.04.4 LTS prints "nan".
In an article on stackoverflow.com, someone found that a change on 2009-08-23 in glibc printf routine is the reason for this: * stdio-common/printf_fp.c: ISO C expects to print the sign of NaN as well. Is there a standard for c++ as to how the iostreams should format a nan? using namespace std; int main() { cout << 0./0. << endl; } -- Summary: Same binary prints sign of nan on different systems. Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: j dot s4403 at gmail dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45762