I'd like to use basic_path as a function parameter so that it works correctly whether a wide or narrow string is passed. template<typename T> void func(basic_path<T> file) { do thing to file } func("myfile"); func(L"myfile"); However I can't do this because basic_path has a second Traits template parameter which is not itself a template. So I tried the following workaround: template<typename T> struct traits_chooser; template<> struct traits_chooser<char*> { typedef boost::filesystem::path_traits traits; }; template<> struct traits_chooser<wchar_t*> { typedef boost::filesystem::wpath_traits traits; }; template<typename T> void func(basic_path<T, typename traits_chooser<T>::traits> file) {...} But my compiler (MSVC 2005) still can't deduce the parameter type. Does anyone know how I can get this to work? Many thanks. Alex Lamaison