fstream provides an iostream interface for file I/O in C++.
The C++ standard library type std::fstream is an iostream type for reading and writing files.
The objects of this class internally maintain a pointer to a std::filebuf object (derived from std::streambuf) that can be obtained/modified by calling the rdbuf member function. The filebuf transfers characters to/from a file and performs any necessary conversion between the on-disk format and the in-memory representation.
For questions specific to fstream use this tag or filebuf, ifstream, ofstream or for more general questions use iostream, istream, ostream or streambuf.
