Apache C++ Standard Library User's Guide

## 45.3 File Streams

### 45.3.1 Connecting Files and Streams

The traditional iostreams supported a file stream constructor, taking a file descriptor that allowed connection of a file stream to an already open file. This is no longer available in the standard-conforming implementation of iostreams.

The functions `attach()` and `detach()` do not exist anymore.

### 45.3.2 The File Buffer

Due to changes in the iostream architecture, the file buffer is now contained as a data member in the file stream templates. In some old implementations, the buffer was inherited from a base class called `fstreambase`.

The old file streams had a destructor; the new file streams don't need one. Flushing the buffer and closing the file is now done by the file buffer's destructor.