1*7c2fbfb3SApril Chinif tst -D_ISOC99_SOURCE -lm note{ _ISOC99_SOURCE plays nice }end link{ 2*7c2fbfb3SApril Chin #include <sys/types.h> 3*7c2fbfb3SApril Chin #include <sys/stat.h> 4*7c2fbfb3SApril Chin #include <stdlib.h> 5*7c2fbfb3SApril Chin #include <unistd.h> 6*7c2fbfb3SApril Chin #include <math.h> 7*7c2fbfb3SApril Chin int main() { return signbit(-0.0); } 8*7c2fbfb3SApril Chin }end { 9*7c2fbfb3SApril Chin #ifndef _ISOC99_SOURCE 10*7c2fbfb3SApril Chin #define _ISOC99_SOURCE 1 11*7c2fbfb3SApril Chin #endif 12*7c2fbfb3SApril Chin } 13*7c2fbfb3SApril Chinendif 14