C++ 101 之 swap收缩容器

#include <iostream>
#include <string>
using namespace std;
#include <vector>


int main()
{
    vector<int> v;
    for(size_t i = 0; i < 10000; i++)
    {
        v.push_back(i);
    }
    cout << "size: " << v.size() << endl;
    cout << "capacity: " << v.capacity() << endl;

    v.resize(3);

    cout << "size: " << v.size() << endl;
    cout << "capacity: " << v.capacity() << endl;

    // 巧用swap收缩内存
    vector<int>(v).swap(v); // 匿名对象：执行完这一句话就会释放
    cout << "size: " << v.size() << endl;
    cout << "capacity: " << v.capacity() << endl;

    
    return 0;
}