ONIG_SYN_OP2_INEFFECTIVE_ESCAPE 799 regint.h !IS_SYNTAX_OP2((syn), ONIG_SYN_OP2_INEFFECTIVE_ESCAPE)) ONIG_SYN_OP2_INEFFECTIVE_ESCAPE 35 regsyntax.c , ONIG_SYN_OP2_INEFFECTIVE_ESCAPE