Standard C++ Library
Copyright 1998, Rogue Wave Software, Inc.
NAME
unary_function
- A base class for creating unary function objects.
SYNOPSIS
#include <functional>
template <class Arg, class Result>
struct unary_function{
typedef Arg argument_type;
typedef Result result_type;
};
DESCRIPTION
Function objects are objects with an operator() defined.
They are important for the effective use of the standard
library's generic algorithms, because the interface for each
algorithmic template can accept either an object with an
operator() defined or a pointer to a function. The standard
library includes both a standard set of function objects and
a pair of classes that you can use as the base for creating
your own function objects.
Function objects that take one argument are called unary
function objects. Unary function objects are required to
include the typedefs argument_type and result_type. The
unary_function class makes the task of creating templatized
unary function objects easier by providing the necessary
typedefs for a unary function object. You can create your
own unary function objects by inheriting from
unary_function.
SEE ALSO
Function_Objects, and Function Objects Section in User's
Guide.