fix private inheritance in regex exception

libwccl/ops/functions/bool/predicates/regex.h

@@ -56,7 +56,7 @@ private:
 	const boost::shared_ptr<const RegexPattern> pattern_;
 };
 
-class RegexParseError : WcclError
+class RegexParseError : public WcclError
 {
 public:
 	RegexParseError(