Hi, I'm trying to compile the following in Visual C++6.0 #include "boost/config.hpp" #include "boost/filesystem/operations.hpp" // includes boost/filesystem/path.hpp #include "boost/filesystem/fstream.hpp" // ditto #include <iostream> // for std::cout using namespace boost::filesystem; int main(int argc, char* argv[]) { remove_all( "foobar" ); create_directory( "foobar" ); boost::filesystem::ofstream file( "foobar/cheeze" ); file << "tastes good!\n"; file.close(); if ( !exists( "foobar/cheeze" ) ) std::cout << "Something is rotten in foobar\n"; return 0; } and I keep getting an error saying that c:\program files\microsoft visual studio\vc98\include\boost\filesystem\fstream.hpp(95) : error C2504: 'basic_ofstream<char,struct std::char_traits<char> >' : base class undefined C:\Program Files\Microsoft Visual Studio\MyProjects\boost_filesystem\boost_filesystem.cpp(17) : see reference to class template instantiation 'boost::filesystem::basic_ofstream<char,struct std::char_traits<char> >' being compiled which I think means that it can't find the implementation for std::basic_ofstream<charT,traits> . I'm not sure how to get around this because I can define a std::basic_ofstream, without problem. Thanks for help, Adam