CC_ESC_WARN(ScanEnv *env, UChar *c)
{
  if (onig_warn == onig_null_warn) return ;

  if (IS_SYNTAX_BV(env->syntax, ONIG_SYN_WARN_CC_OP_NOT_ESCAPED) &&
      IS_SYNTAX_BV(env->syntax, ONIG_SYN_BACKSLASH_ESCAPE_IN_CC)) {
    onig_syntax_warn(env, "character class has '%s' without escape", c);
  }
}
Unknown