cpp/io/ios base

The class is a multipurpose class that serves as the base class for all I/O stream classes. It maintains several kinds of data:

@1@ state information: stream status flags. @2@ control information: flags that control formatting of both input and output sequences and the imbued locale. @3@ private storage: indexed extensible data structure that allows both and  members, which may be implemented as two arbitrary-length arrays or a single array of two-element structs or another container. @4@ callbacks: arbitrary number of user-defined functions to be called from, std, and.

Typical implementation holds member constants corresponding to all values of, , , and shown below, member variables to maintain current precision, width, and formatting flags, the exception mask, the buffer error state, a resizeable container holding the callbacks, the currently imbued locale, the private storage, and a static integer variable for.