HAVE_ISNAN        160 include/ruby/missing.h #  if defined(HAVE_FINITE) && defined(HAVE_ISNAN)
HAVE_ISNAN        172 include/ruby/missing.h # ifndef HAVE_ISNAN
HAVE_ISNAN         23 missing/isinf.c #if defined(HAVE_FINITE) && defined(HAVE_ISNAN)