make a big vector and then deallocate all its memory : vector capacity « vector « C++ Tutorial

1. C++ Tutorial
2. vector
3. vector capacity

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

using namespace std;

int main( )
{
   // make a big vector and then deallocate all its memory
   const int big_size = 10000;
   vector<double> v( big_size );
   cout << "Before clearing, the capacity of the vector is "
      << v.capacity() << " and its size is " << v.size();
   v.clear();
   cout << "\nAfter clearing, the capacity of the vector is "
      << v.capacity() << " and its size is " << v.size();
   vector<double>().swap( v );

   cout << "\nAfter swapping, the capacity of the vector is "
      << v.capacity() << " and its size is " << v.size();

}