A class that is the parent of another class. The base class defines the interface that a derived class inherits.
condition state
Flags and associated functions usable by any of the stream classes that indicate whether a given stream is usable. States and functions to get and set these states are listed in Table 8.2 (p. 288).
derived class
A derived class is one that shares an interface with its parent class.
file mode
Flags defined by the fstream classes that are specified when opening a file and control how a file can be used. Listed in Table 8.3 (p. 297).
fstream
Stream object that reads or writes a named file. In addition to the normal iostream operations, the fstream class also defines open and close members. The open member function takes a C-style character string that names the file to open and an optional open mode argument. By default ifstreams are opened with in mode, ofstreams with out mode, and fstreams with in and out mode set. The close member closes the file to which the stream is attached. It must be called before another file can be opened.
inheritance
Types that are related by inheritance share a common interface. A derived class inherits properties from its base class. Chapter 15 covers inheritance.
object-oriented library
A set of classes related by inheritance. Generally speaking, the base class of an object-oriented library defines an interface that is shared by the classes derived from that base class. In the IO library, the istream and ostream classes serve as base classes for the types defined in the fstream and sstream headers. We can use an object of a derived class as if it were an object of the base class. For example, we can use the operations defined for istream on an ifstream object.
stringstream
Stream object that reads or writes a string. In addition to the normal iostream operations, it also defines an overloaded member named str. Calling str with no arguments returns the string to which the stringstream is attached. Calling it with a string attaches the stringstream to a copy of that string.
