-std::set<std::string> created_categories;
-std::set<std::string> declared_marks;
-std::set<std::string> user_host_variables;
-std::set<std::string> user_vm_variables;
-std::set<std::string> user_link_variables;
+std::set<std::string, std::less<>> created_categories;
+std::set<std::string, std::less<>> declared_marks;
+std::set<std::string, std::less<>> user_host_variables;
+std::set<std::string, std::less<>> user_vm_variables;
+std::set<std::string, std::less<>> user_link_variables;