ONIG_SYN_OP2_INEFFECTIVE_ESCAPE  634 ext/mbstring/oniguruma/regint.h    !IS_SYNTAX_OP2((syn), ONIG_SYN_OP2_INEFFECTIVE_ESCAPE))
ONIG_SYN_OP2_INEFFECTIVE_ESCAPE   34 ext/mbstring/oniguruma/regsyntax.c   , ONIG_SYN_OP2_INEFFECTIVE_ESCAPE