STL Sample for the binary_function Structure

• The Standard C++ Library included with: - Microsoft Visual C++, 32-bit Edition, version 4.2

SUMMARY

The sample code below illustrates how to use the binary_function STL structure in Visual C++.

MORE INFORMATION

Required Header

   < functional >

Prototype

   template<class _A1, class _A2, class _R>
   struct binary_function
   {
     typedef _A1 first_argument_type;
     typedef _A2 second_argument_type;
     typedef _R result_type;
   };

Description

The binary_function<A,B,C> class is used as a base class to allow the user to easily define binary operator functions that take data types A and B as arguments and return data type C objects.

Sample Code

////////////////////////////////////////////
//
// Compile options needed: /GX
//
// binfunc.cpp : Illustrating the binary_function
//               structure.
//
// Structure used: binary_function<A,B,C> - base
//                 class used to create operator
//                 functions taking data types A
//                 and B and returning data type C.
//
// Written by Mark Hagen
// of Microsoft Product Support Services,
// Copyright (c) 1996 Microsoft Corporation.
// All rights reserved.
////////////////////////////////////////////

#include <functional>
#include <iostream>

  float value;
  binary_test(){value=10.0;}
  binary_test(float x){value=x;}
  result_type operator<<(second_argument_type arg2);

binary_test::result_type binary_test::operator<<(binary_test::second_argument_type arg2) {

  value = ((int)value) << arg2;
  cout << "New value after shift is" << value << endl;
  return value;

void main(void)

  binary_test item;

  cout << "Begin" << endl;
  item = item << 2;

Program Output is:

Begin New value after shift is 40.0

REFERENCES

Visual C++ Books On Line: Visual C++ Books:C/C++:Standard C++ Library Reference.