Q158580: STL Sample for the set::(swap, begin, end) Function

Article: Q158580
Product(s): Microsoft C Compiler
Version(s): 4.2,5.0,6.0
Operating System(s): 
Keyword(s): kbcode kbtemplate kbSTL kbVC420 kbVC500 kbVC600 kbDSupport
Last Modified: 29-APR-2002

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The information in this article applies to:

- The Standard C++ Library, used with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, versions 4.2, 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, versions 4.2, 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
   - Microsoft Visual C++.NET (2002) 
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NOTE: Microsoft Visual C++ NET (2002) supported both the managed code model that is provided by the .NET Framework and the unmanaged native Windows code model. The information in this article applies to unmanaged Visual C++ code only.

SUMMARY
=======

The following sample code illustrates how to use the set::swap, set::begin and
set::end STL functions in Visual C++.

MORE INFORMATION
================

Required Header
---------------

     <set>

Prototype
---------

     template<class _K, class _Pr, class _A>
     class set {
     public:
     // Function 1:

        void swap(_Myt& _X);
     // Function 2:
        friend void swap(_Myt& _X, _Myt& _Y);
     // Function 3:
        const_iterator begin() const;
     // Function 4:
        const_iterator end() const;
     }

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

Description
-----------

The swap function swaps the two controlled sequences. The begin function returns
a bidirectional iterator that points at the first element of the sequence. The
end function returns a bidirectional iterator that points just beyond the end of
the sequence.

Sample Code
-----------

  ////////////////////////////////////////////////////////////////////// 
  // 
  // Compile options needed: -GX
  // 
  // SetSwapBeginEnd.cpp:
  //      Illustrates how to use the swap function to exchange the two
  //      controlled sequences. It also illustrates how to use the
  //      begin function to get a bidirectional iterator that points at
  //      the first element of the controlled sequence. Finally, it
  //      illustrates how to use the end function to get a bidirectional
  //      iterator that points just beyond the end of the controlled
  //      sequence.
  // 
  // Functions:
  // 
  //    swap        Exchanges the two controlled sequences.
  //    begin       Returns a bidirectional iterator that points at the
  //                first element of the controlled sequence.
  //    end         Returns a bidirectional iterator that points just
  //                beyond the end of the controlled sequence.
  // 
  // Written by Derek Jamison
  // of Microsoft Technical Support,
  // Copyright (c) 1996 Microsoft Corporation. All rights reserved.
  ////////////////////////////////////////////////////////////////////// 

  #pragma warning(disable:4786)

  #include <set>
  #include <iostream>

  #if _MSC_VER > 1020   // if VC++ version is > 4.2
     using namespace std;  // std c++ libs implemented in std
     #endif

  typedef set<int,less<int>,allocator<int> > SET_INT;

  void main() {

    SET_INT s1;
    SET_INT s2;
    SET_INT::iterator i;
    cout << "s1.insert(5)" << endl;
    s1.insert(5);
    cout << "s1.insert(10)" << endl;
    s1.insert(10);
    cout << "s1.insert(15)" << endl;
    s1.insert(15);
    cout << "s2.insert(2)" << endl;
    s2.insert(2);
    cout << "s2.insert(4)" << endl;
    s2.insert(4);

    cout << "swap(s1,s2)" << endl;
    swap(s1,s2);

    // Displays: 2,4

    for (i=s1.begin();i!=s1.end();i++)

       cout << "s1 has " << *i << " in its set." << endl;

    // Displays: 5,10,15

    for (i=s2.begin();i!=s2.end();i++)

       cout << "s2 has " << *i << " in its set." << endl;

    cout << "s1.swap(s2)" << endl;
    s1.swap(s2);

    // Displays: 5,10,15

    for (i=s1.begin();i!=s1.end();i++)

       cout << "s1 has " << *i << " in its set." << endl;

    // Displays: 2,4

    for (i=s2.begin();i!=s2.end();i++)

       cout << "s2 has " << *i << " in its set." << endl;

  }

Program Output
--------------

  s1.insert(5)
  s1.insert(10)
  s1.insert(15)
  s2.insert(2)
  s2.insert(4)
  swap(s1,s2)
  s1 has 2 in its set.
  s1 has 4 in its set.
  s2 has 5 in its set.
  s2 has 10 in its set.
  s2 has 15 in its set.
  s1.swap(s2)
  s1 has 5 in its set.
  s1 has 10 in its set.
  s1 has 15 in its set.
  s2 has 2 in its set.
  s2 has 4 in its set.

REFERENCES
==========

Visual C++ Books Online: Visual C++ Books; C/C++; Standard C++ Library Reference

Additional query words: STL STLSample swap begin end

======================================================================
Keywords          : kbcode kbtemplate kbSTL kbVC420 kbVC500 kbVC600 kbDSupport 
Technology        : kbVCsearch kbAudDeveloper kbVCLibrary
Version           : :4.2,5.0,6.0
Issue type        : kbinfo

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