#include <iostream>
using namespace std;

int main()
{
    string str("std::String");
    for (int i=0; i<20; ++i)
    {
        cout << "capacity is " << str.capacity() << endl;
        str += " ,is Overrun safe string";
    }
    return 0;
}

capacity is 11
capacity is 35
capacity is 70
capacity is 140
capacity is 140
capacity is 140
capacity is 280
capacity is 280
capacity is 280
capacity is 280
capacity is 280
capacity is 280
capacity is 560
capacity is 560
capacity is 560
capacity is 560
capacity is 560
capacity is 560
capacity is 560
capacity is 560