When we use sysconf(_SC_NPROCESSORS_ONLN) to get number of
cores, we have to include sysconf library that is unistd.h
Sometimes it happens to work just becuase unistd.h indirectly
included by some other libraries, but not always.
Reported and fixed by Eyal BD
No functional change.
#else
# include <inttypes.h>
#else
# include <inttypes.h>
+# include <unistd.h> // Used by sysconf(_SC_NPROCESSORS_ONLN)
#endif
#if !defined(_WIN32) && !defined(_WIN64) // Linux - Unix
#endif
#if !defined(_WIN32) && !defined(_WIN64) // Linux - Unix