STL Sample for the Generate Function

Last reviewed: October 9, 1997
Article ID: Q156079
The information in this article applies to:
  • 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 generate STL function in Visual C++.

MORE INFORMATION

Required Header

<algorithm>

Prototype

template<class InputIterator, class Function> inline

    Function for_each(InputIterator first,
                      InputIterator last,
                      Function F)
template<class ForwardIterator, class Generator> inline
 void generate(ForwardIterator first, ForwardIterator last, Generator gen)

NOTE: The class/parameter names in the prototype do not match the version in the header file. Some have been modified to improve readability.

Description

The Generate algorithm traverses the range [first, last + 1), assigning to each element the value returned by gen. Generate modifies the elements in the specified range.

Sample Code

//////////////////////////////////////////////////////////////////////
//
// Compile options needed: /GX
//
// generate.cpp : Illustrates how to use the generate function.
//
// Functions:
//
//   generate - Fill a sequence using a generator function
//   Fibonacci - return the next Fibonacci number in the
//               Fibonacci series.
//
// Written by Kalindi Sanghrajka
// of Microsoft Product Support Services,
// Software Core Developer Support.
// Copyright (c) 1996 Microsoft Corporation. All rights reserved.
//////////////////////////////////////////////////////////////////////

// disable warning C4786: symbol greater than 255 character,
// okay to ignore
#pragma warning(disable: 4786)

#include <iostream>
#include <vector>
#include <algorithm>

// return the next Fibonacci number in the
// Fibonacci series.
int Fibonacci(void)
{
    static int r;
    static int f1 = 0;
    static int f2 = 1;
    r = f1 + f2 ;
    f1 = f2 ;
    f2 = r ;
    return f1 ;
}

void main()
{
    const int VECTOR_SIZE = 8 ;

    // Define a template class vector of integers
    typedef vector<int, allocator<int> > IntVector ;

    //Define an iterator for template class vector of integer
    typedef IntVector::iterator IntVectorIt ;

    IntVector Numbers(VECTOR_SIZE) ;   //vector containing numbers

    IntVectorIt start, end, it ;

    start = Numbers.begin() ;   // location of first
                                // element of Numbers

    end = Numbers.end() ;       // one past the location
                                // last element of Numbers


    // fill the range [first, last +1) with a series of
    // Fibonnaci numbers using the Fibonacci function
    generate(start, end, Fibonacci) ;

    // print content of Numbers
    cout << "Numbers { " ;
    for(it = start; it != end; it++)
        cout << *it << " " ;
    cout << " }\n" << endl ;
}

Program Output is:

Numbers { 1 1 2 3 5 8 13 21 }

REFERENCES

Visual C++ Books Online; click "Visual C++ Books," "C/C++," then "Standard C++ Library Reference."


Additional query words: STL generate
Keywords : STLIss kbcode
Version : WINNT:4.2;
Platform : NT WINDOWS
Issue type : kbhowto


THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Last reviewed: October 9, 1997
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.