[Boost-users] mapped_file_sink

I'm trying to create memory mapped files using mapped_file_sink: mapped_file_params mfParams( fileName ); mfParams.new_file_size = filesize; mapped_file_sink mfSink( mfParams ); trying to use any of its funtions like: const char *ptStart = mfSink.data(); the compiler tells me that I have no access to them for they are private members since inherited from mapped_file I know thats a piece of cake but just cant solve it. Cheers Alf