Can someone else confirm that Boost v1.55 beta is not compiling on VS2013 RC? I see lots of this: 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(42): error C2065: 'ReadableIterator' : undeclared identifier 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(42): error C2065: 'Iterator' : undeclared identifier 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(43): error C2448: 'BOOST_concept' : function-style initializer appears to be a function definition 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(43): error C2143: syntax error : missing ';' before ':' 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(43): error C2065: 'Iterator' : undeclared identifier 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(43): error C2923: 'boost::Assignable' : 'Iterator' is not a valid template type argument for parameter 'TT' 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(44): error C2143: syntax error : missing ';' before ',' 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(44): error C2059: syntax error : ',' 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(44): error C2065: 'Iterator' : undeclared identifier 2>G:\TripleGit\boost\boost/iterator/iterator_concepts.hpp(44): error C2923: 'boost::CopyConstructible' : 'Iterator' is not a valid template type argument for parameter 'TT' .... Here is the really weird thing - the macro BOOST_concept appears to not be defined, so if you do a: #ifndef BOOST_concept #error Hello #endif ... you get error Hello. Methinks this is a compiler bug in the RC, but can anyone else confirm? Niall -- Currently unemployed and looking for work. Work Portfolio: http://careers.stackoverflow.com/nialldouglas/