When using this type: boost::spirit::position_iteratorstd::string::const_iterator I get a static assertion failure: ..\..\lib\boost_1_37_0\boost/iterator/iterator_adaptor.hpp(230) : error C2027: u se of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' with [ x=false ] ..\..\lib\boost_1_37_0\boost/iterator/iterator_adaptor.hpp(335) : see re ference to function template instantiation 'void boost::detail::iterator_adaptor _assert_traversal(void)' being compiled ..\..\lib\boost_1_37_0\boost/iterator/iterator_adaptor.hpp(334) : while compiling class template member function 'void boost::iterator_adaptor::advance(__w64 int)' with [ Derived=boost::spirit::position_iterator>, Base=std::_String_const_iterator, Value=const char, Traversal=boost::forward_traversal_tag ] ..\..\lib\boost_1_37_0\boost/spirit/home/classic/iterator/position_itera tor.hpp(156) : see reference to class template instantiation 'boost::iterator_ad aptor' being compiled with [ Derived=boost::spirit::position_iterator>, Base=std::_String_const_iterator, Value=const char, Traversal=boost::forward_traversal_tag ] source/eldwood/core/lexer.cpp(81) : see reference to class template inst antiation 'boost::spirit::position_iterator<ForwardIteratorT>' being compiled with [ ForwardIteratorT=std::_String_const_iterator ] This is triggered on a simple function declaration taking a position_iterator as argument, using MSVC8.0 Express on Windows XP. It worked under Boost 1.36.0. -- Rainer Deyke - rainerd@eldwood.com