Q156590: STL Sample for deque::erase and deque::clear Functions

Article: Q156590
Product(s): Microsoft C Compiler
Version(s): 4.2,5.0,6.0
Operating System(s): 
Keyword(s): kbcode kbVC420 kbVC500 kbVC600 kbDSupport
Last Modified: 26-MAR-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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SUMMARY
=======

The sample code below illustrates how to use the deque::erase, deque::clear,
deque::begin, and deque::end STL functions in Visual C++.

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

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

     < deque>

Prototype
---------

     iterator erase(iterator iter);
     iterator erase(iterator first, iterator last);
     void clear() 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 first erase member function removes the element of the container pointed to
by iter. The second erase member function removes the elements of the container
in the range [first, last). Both return an iterator that designates the first
element remaining beyond any elements removed, or end() if no such element
exists.

Removing N elements causes N destructor calls and an assignment for each of the
elements between the insertion point and the nearer end of the sequence.

Removing an element at either end invalidates only iterators and references that
designate the erased elements. Otherwise, erasing an element invalidates all
iterators and references.

The clear member function calls erase( begin(), end()).

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

NOTE: In the first line of the sample code section, /GX is equivalent to /EHsc in
VC++ .NET and is set by default.

  ////////////////////////////////////////////////////////////////////// 
  // 
  // Compile options needed: -GX
  // 
  // deque.cpp :
  // 
  // Functions:
  // 
  //    erase
  //    clear
  //    begin
  //    end
  // 
  // Written by Bobby Mattappally
  // of Microsoft Product Support Services,
  // Copyright (c) 1996 Microsoft Corporation. All rights reserved.
  ////////////////////////////////////////////////////////////////////// 

  /* Compile options needed:-GX
  */ 
  #include <iostream>
  #include <deque>

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

  typedef deque<int, allocator<int> >  INTDEQUE;

  void print_contents (INTDEQUE  deque);

  void main()

  {

      // create a and with elements 1,2,3,4 and 5
      INTDEQUE  a;
      a.push_back(1);
      a.push_back(2);
      a.push_back(3);
      a.push_back(4);
      a.push_back(5);

      //print the contents
      print_contents (a);

      //  erase the second element
      a.erase(a.begin()+1);
      print_contents (a);

      //erase the last two elements
      a.erase(a.end()-2,a.end());
      print_contents (a);

      //clear a
      a.clear();
      print_contents (a);

  }

  void print_contents (INTDEQUE  deque) {
      INTDEQUE::iterator pdeque;

      cout <<"The output is: ";

          for(pdeque = deque.begin();
          pdeque != deque.end();
          pdeque++)
      {
          cout << *pdeque <<" " ;
      }
          cout<<endl;

  }

Program Output is:

The output is: 1 2 3 4 5
The output is: 1 3 4 5
The output is: 1 3
The output is:

REFERENCES
==========

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

Additional query words: STL STLSample erase clear begin end

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

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