Reading file all at once

Few times, you would want to read the whole file in one go, not line by line, not by a fixed buffer size. Here's a way to get that done:

    std::fstream ifs("filename.txt");
    if (!ifs)
    {
         std::stringstream oss;
         oss << ifs.rdbuf();
    }

As simple as that. The contents of the file are moved (re-directed) to the stringstream. The same code can be used to make copies of files. You would need to replace the stringstream object with an fstream one though.