ONIG_OPTION_POSIX_REGION  419 include/ruby/oniguruma.h #define ONIG_OPTION_ASCII_RANGE          (ONIG_OPTION_POSIX_REGION << 1)
ONIG_OPTION_POSIX_REGION  438 regint.h       #define IS_POSIX_REGION(option)   ((option) & ONIG_OPTION_POSIX_REGION)