[boost] [unordered] 1.48 beta1 fails to compile with MSVC 2010 SP 1, error C2027: use of undefined type 'boost::type'

After trying out beta 1, I am seeing some failures with unordered containers, see attached file. Microsoft (R) C/C++ Optimizing Compiler Version 16.00.40219.01 for x64 The code compiles without problems under 1.47.0. Unfortunately, I cannot yet publish the source code that triggers this problem. Any hints where to start investigating this? -- /Johan.