HOWTO: STL Sample for [list::rbegin, rend, reverse, rev_iterator]
ID: Q168046
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The information in this article applies to:
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The Standard C++ Library, used with:
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Microsoft Visual C++, 32-bit Editions, versions 4.2, 5.0, 6.0
SUMMARY
The sample code below illustrates how to use the [list::rbegin, list::rend,
list::reverse_iterator, list::reverse] STL function(s) in Visual C++.
NOTE: There are some differences in the implementation of the Standard
C++ Library components in Visual C++ version 4.2 versus later revisions.
The relevant sections of code below compile conditionally based upon the
value of _MSC_VER.
MORE INFORMATION
Required Header
<list>
<string>
<iostream>
Prototype
const_reverse_iterator rbegin() const;
reverse_iterator rbegin();
const_reverse_iterator rend() const;
reverse_iterator rend();
typedef reverse_bidirectional_iterator<iterator,
value_type, reference, A::types<T>::pointer,
difference_type> reverse_iterator;
void reverse();
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
This example shows how to iteratate through a list backwards. It also shows
how to reverse a list.
Sample Code
//////////////////////////////////////////////////////////////////////
//
// Compile options needed: -GX
//
// rev.cpp : This example shows how to iteratate through a list
// backwards. It also shows how to reverse a list.
//
// Functions:
//
// list::rbegin
// list::rend
// list::reverse_iterator
// list::reverse
//
// Written by Andrew Bradnan
// Copyright (c) 1996 Microsoft Corporation. All rights reserved.
//////////////////////////////////////////////////////////////////////
#pragma warning(disable:4786)
#include <list>
#include <string>
#include <iostream>
#if _MSC_VER > 1020 // if VC++ version is > 4.2
using namespace std; // std c++ libs implemented in std
#endif
typedef list<string, allocator<string> > LISTSTR;
// We use this object so that list::sort() can sort in a different
// order.Normally greater<> is used. We override it here to switch to
// less.
struct less_str : greater<string> {
bool operator()(const string& _X, const string& _Y) const
{return (_X < _Y); }
};
void main()
{
LISTSTR test;
LISTSTR::iterator i;
LISTSTR::reverse_iterator r;
test.push_back("one");
test.push_back("two");
test.push_back("three");
// one two three
cout << "Forwards" << endl << " ";
for (i = test.begin(); i != test.end(); ++i)
cout << *i << " ";
cout << endl;
// three two one
cout << "Backwards" << endl << " ";
for (r = test.rbegin(); r != test.rend(); ++r)
cout << *r << " ";
cout << endl;
// Switch the order
test.reverse();
// three two one
cout << "Reversed" << endl << " ";
for (i = test.begin(); i != test.end(); ++i)
cout << *i << " ";
cout << endl;
// sort alphabetically (decending by default)
test.sort();
// two three one
cout << "Sorted descending" << endl << " ";
for (i = test.begin(); i != test.end(); ++i)
cout << *i << " ";
cout << endl;
test.sort(less_str());
// One three two
cout << "Sorted ascending" << endl << " ";
for (i = test.begin(); i != test.end(); ++i)
cout << *i << " ";
cout << endl;
}
Program Output
Forwards
one two three
Backwards
three two one
Reversed
three two one
Sorted descending
one three two
Sorted ascending
two three one
REFERENCES
Visual C++ Books On Line: Visual C++ Books:C/C++:Standard C++ Library
Reference.
Additional query words:
STL STLSample [list::rbegin, list::rend, list::reverse_iterator, list::reverse]
Keywords : kbcode kbVC420 kbVC500 kbVC600 STLIss
Version : winnt:4.2,5.0,6.0
Platform : winnt
Issue type : kbhowto