// reverse algorithm example
#include <iostream>     // std::cout
#include <algorithm>    // std::reverse
#include <vector>       // std::vector

int main () {
  std::vector<int> myvector;

  // set some values:
  for (int i=1; i<10; ++i) myvector.push_back(i);   // 1 2 3 4 5 6 7 8 9

  std::reverse(myvector.begin(),myvector.end());    // 9 8 7 6 5 4 3 2 1

  // print out content:
  std::cout << "myvector contains:";
  for (std::vector<int>::iterator it=myvector.begin(); it!=myvector.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';

  return 0;
}

 1 // swap algorithm example (C++98)
 2 #include <iostream>     // std::cout
 3 #include <algorithm>    // std::swap
 4 #include <vector>       // std::vector
 5 
 6 int main () {
 7 
 8   int x=10, y=20;                              // x:10 y:20
 9   std::swap(x,y);                              // x:20 y:10
10 
11   std::vector<int> foo (4,x), bar (6,y);       // foo:4x20 bar:6x10
12   std::swap(foo,bar);                          // foo:6x10 bar:4x20
13 
14   std::cout << "foo contains:";
15   for (std::vector<int>::iterator it=foo.begin(); it!=foo.end(); ++it)
16     std::cout << ' ' << *it;
17   std::cout << '\n';
18 
19   return 0;
20 }