I have been puzzled by the effect of my mistyping causing this message. i:\trunk\boost/range/const_iterator.hpp(37) : error C2039: 'const_iterator' : is not a member of 'std::ios_base' C:\Program Files\Microsoft Visual Studio 8\VC\include\xiosbase(183) : see declaration of 'std::ios_base' i:\trunk\boost/mpl/eval_if.hpp(63) : see reference to class template instantiation 'boost::range_const_iterator<C>' being compiled with [ C=std::ios_base ] i:\trunk\boost/range/iterator.hpp(63) : see reference to class template instantiation 'boost::mpl::eval_if_c<C,F1,F2>' being compiled with [ C=true, F1=boost::range_const_iterator<std::ios_base>, F2=boost::range_mutable_iterator<const std::ios_base> ] I:\Boost-sandbox\SOC\2007\visualization\boost/svg_plot/show_2d_settings.hpp(104) : see reference to class template instantiation 'boost::range_iterator<C>' being compiled with [ C=const std::ios_base ] i:\trunk\boost/range/const_iterator.hpp(37) : error C2146: syntax error : missing ';' before identifier 'type' i:\trunk\boost/range/const_iterator.hpp(37) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int i:\trunk\boost/range/const_iterator.hpp(37) : error C2208: 'boost::type' : no members defined using this type i:\trunk\boost/range/const_iterator.hpp(37) : fatal error C1903: unable to recover from previous error(s); stopping compilation The "erroneous" line 37 is: template< typename C > struct range_const_iterator { typedef BOOST_DEDUCED_TYPENAME C::const_iterator type; }; And this left me in total disambiguation mode :-) The cause was simple - I typed ">> end;" when I wanted ">> endl;" In mitigation I would point out that I got the other 120 endl;'s right ;-) The compiler, lack an ounce of sense, interpreted this to the letter. I suspect I may not be first or last person to do this :-) Could the source file usefully have a comment that says something like " If you get a error "'const_iterator' : is not a member of 'std::ios_base'" here have you typed "end;" somewhere instead of "endl;" " ? Paul --- Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB +44 1539561830 & SMS, Mobile +44 7714 330204 & SMS pbristow@hetp.u-net.com --- Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB +44 1539561830 & SMS, Mobile +44 7714 330204 & SMS pbristow@hetp.u-net.com