Hi, I've recently been reworking some filereaders and changed them from std::iostream to boost::iostreams::mapped_file_source. Though the data has been fully loaded the std::getline() did set only the first character of the text and returned false, which caused the usual while loop to exit. When I wanted to ask you for help and made up a small example, in which the filereading - to my surprise - worked fine. The problem has been, that from rewritting from the code from std::iostreams there was an std::ios::in left. So my actual filereading looked like this: io::mapped_file_source file("C://test.txt", std::ios::in); io::stream<io::mapped_file_source> input(file); std::string line; while(std::getline(input, line)) { std::cout << "Line: " << line << std::endl; } After removing the std::ios::in everything worked as expected. All tests have been made using Boost 1.37 and MSVC8. My question is if this is the intended behaviour of mapped_file_source and if so, if that could be pointed out more prominently in the docs, since I think I've virtually read all of them and didn't find anything similiar in there. cheers, Norbert