cpp/io/basic istream

The class template provides support for high level input operations on character streams. The supported operations include formatted input (e.g. integer values or whitespace-separated characters and characters strings) and unformatted input (e.g. raw characters and character arrays). This functionality is implemented in terms of the interface provided by the underlying class, accessed through the  base class. The only non-inherited data member of, in most implementations, is the value returned by.

Global objects
Two global basic_istream objects are provided by the standard library.