Hello, I'm still having troubles with Boost.Serialization in Boost 1.41. The following example code fails to compile with latest Boost release, while it works with 1.39: #include <boost/archive/binary_iarchive.hpp> #include <boost/serialization/shared_ptr.hpp> #include <boost/shared_ptr.hpp> #include <iostream> // dummy struct with no actual serialization code struct Test { template<typename A> void serialize(A &, unsigned) {} }; int main() { boost::archive::binary_iarchive ia(std::cin); boost::shared_ptr<Test> x; ia & x; return 0; } The compiler (MSVC 9) gives me this error: error C2440: 'return' : cannot convert from 'const boost::serialization::extended_type_info_typeid<T>' to 'const boost::serialization::extended_type_info *'c:\boost\include\boost-1_41\boost\archive\shared_ptr_helper.hppIt seems that an address-of (&) operator is required in shared_ptr_helper.hpp at line 111, that is: ... return boost::serialization::singleton< ... should read: ... return &boost::serialization::singleton< ... This change makes my code compile, but I'm not sure whether it's an appropriate fix or not, as I don't know Serialization's internals. Cheers, Marco