diff --git a/library/DataIdentity.cpp b/library/DataIdentity.cpp
index c041b009d..31df1078c 100644
--- a/library/DataIdentity.cpp
+++ b/library/DataIdentity.cpp
@@ -49,7 +49,9 @@ namespace df {
     STL_OPAQUE_IDENTITY_TRAITS(mutex);
     STL_OPAQUE_IDENTITY_TRAITS(future<void>);
     STL_OPAQUE_IDENTITY_TRAITS(function<void()>);
-    STL_OPAQUE_IDENTITY_TRAITS(optional<std::function<void()> >);
+    STL_OPAQUE_IDENTITY_TRAITS(optional<void_function>);
+    OPAQUE_IDENTITY_TRAITS_NAME(std::variant<std::string COMMA void_function>,
+        "variant<string, void_function>");
 
     buffer_container_identity buffer_container_identity::base_instance;
 }
diff --git a/library/include/DataIdentity.h b/library/include/DataIdentity.h
index 035f59d4b..dad9f44cc 100644
--- a/library/include/DataIdentity.h
+++ b/library/include/DataIdentity.h
@@ -31,6 +31,7 @@ distribution.
 #include <sstream>
 #include <string>
 #include <unordered_map>
+#include <variant>
 #include <vector>
 
 #include "DataDefs.h"
@@ -576,7 +577,11 @@ namespace df
     OPAQUE_IDENTITY_TRAITS(std::mutex);
     OPAQUE_IDENTITY_TRAITS(std::future<void>);
     OPAQUE_IDENTITY_TRAITS(std::function<void()>);
-    OPAQUE_IDENTITY_TRAITS(std::optional<std::function<void()> >);
+
+    typedef std::function<void()> void_function;
+    #define COMMA ,
+    OPAQUE_IDENTITY_TRAITS(std::optional<void_function>);
+    OPAQUE_IDENTITY_TRAITS(std::variant<std::string COMMA void_function>);
 
 #ifdef BUILD_DFHACK_LIB
     template<typename T>
diff --git a/library/xml b/library/xml
index bdf4b660d..e049cb4df 160000
--- a/library/xml
+++ b/library/xml
@@ -1 +1 @@
-Subproject commit bdf4b660d5282fdf722293609675a633fd5a641e
+Subproject commit e049cb4df86d116689c0ef84bf1962d282b7b880