ONIG_SYN_OP2_INEFFECTIVE_ESCAPE 662 regint.h !IS_SYNTAX_OP2((syn), ONIG_SYN_OP2_INEFFECTIVE_ESCAPE)) ONIG_SYN_OP2_INEFFECTIVE_ESCAPE 34 regsyntax.c , ONIG_SYN_OP2_INEFFECTIVE_ESCAPE