Hi Robert, My build is currently failing on master due to the following friend declaration in array.hpp: [...] public: // note: I would like to make the copy constructor private but this breaks // make_array. So I try to make make_array a friend - but that doesn't // build. Need a C++ guru to explain this! template<class S> friend const boost::serialization::array_wrapper<T> make_array( T* t, S s); [...] actual definition: template<class T, class S> inline const array_wrapper< T > make_array( T* t, S s){ const array_wrapper< T > a(t, s); return a; } the problem is that the actual template definition takes two template parameters. Has a result, the friend declaration introduces a new template that will be missing at link time. I'd like to have it fixed for the upcomming release so that we could merge in a long overdue update of the MPI lib. The fix seems kind of trivial: https://github.com/boostorg/serialization/pull/46 I also have an issue with the selection criteria for emplace_hint which fails (at least) on intel C++/CentOS 6.5: https://github.com/boostorg/serialization/pull/47 Regards Alain