When building CVS Boost with MSVC 8 beta 2 (http://lab.msdn.microsoft.com/vs2005/), it generated the errors below for iostreams. operations.hpp has a mixture of line endings, and symmetric_filter_adapter_impl is missing a return type, so I guess it's telling the truth! - KM F:\CVS\boost\boost/iostreams/operations.hpp : error C4335: Mac file format detected: please convert the source file to either DOS or UNIX format F:\CVS\boost\boost/type_traits/is_abstract.hpp(81) : warning C4800: 'unsigned int' : forcing value to bool 'true' or 'false' (performance warning) F:\CVS\boost\boost/type_traits/is_abstract.hpp(93) : see reference to class template instantiation 'boost::detail::is_abstract_imp2<T>' being compiled F:\CVS\boost\boost/iostreams/filter/symmetric_filter_adapter.hpp(303) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int F:\CVS\boost\boost/iostreams/filter/symmetric_filter_adapter.hpp(303) : error C2063: 'symmetric_filter_adapter_impl' : not a function F:\CVS\boost\boost/iostreams/filter/symmetric_filter_adapter.hpp(303) : error C2888: 'symmetric_filter_adapter<SymmetricFilter,Alloc>::symmetric_filter_adapter_impl symmetric_filter_adapter_impl' : symbol cannot be defined within namespace 'iostreams' F:\CVS\boost\boost/iostreams/filter/symmetric_filter_adapter.hpp(303) : fatal error C1903: unable to recover from previous error(s); stopping compilation