fix size

src/utils/workers/result.hpp

@@ -34,6 +34,12 @@ namespace hr
       return res;
     }
 
+    std::size_t size()
+    {
+      if (!empty()) return m_data.at(0).m_value.size();
+      else return 0;
+    }
+
     std::vector<bit> m_data;
   };
 }