Make certain that the C++ standard you’re using is compatible with your boost version. Make certain that the compiler version you’re using is supported by the boost version you’re using. Both compilers you’re using are ancient. From: Boost-users On Behalf Of Daniel via Boost-users Sent: Wednesday, July 31, 2024 10:56 PM To: boost-users@lists.boost.org Cc: Daniel Subject: [Boost-users] undefined type on vs2008 but not vs2010 Hi, I'm new to C++, working on an old project using the vs2008 toolset. I need to add some networking and so I started with the docs tutorial "An asynchronous TCP daytime server". Boost 1.68 Error C2027 use of undefined type 'boost::_bi::add_cref' BoostAsio d:\downloads\boost_1_68_0\boost\bind\bind.hpp 2323 namespace _bi { template< class Pm, int I > struct add_cref; ... template struct dm_result { typedef typename add_cref< Pm, 1 >::type type; <<< 2323 }; Do I need to provide more details? Thanks