#if BOOST_VERSION < 108000

gtsam/base/std_optional_serialization.h

@@ -11,6 +11,8 @@
 
 // Defined only if boost serialization is enabled
 #ifdef GTSAM_ENABLE_BOOST_SERIALIZATION
+// Only for old boost
+#if BOOST_VERSION < 108000
 #pragma once
 #include <optional>
 #include <boost/config.hpp>
@@ -99,3 +101,4 @@ void serialize(Archive& ar, std::optional<T>& t, const unsigned int version) {
 }  // namespace serialization
 }  // namespace boost
 #endif
+#endif