c++ 指定长度容器元素的拷贝（copy_n）

#include <iostream>     // cout

#include <algorithm>    // copy

#include <vector>       // vector

using namespace std;

int main () {

    int myints[]={10,20,30,40,50,60,70};

    vector<int> myvector;

    myvector.resize(2);   // allocate space for 7 elements

    copy_n ( myints, 5, myvector.begin() );

    cout << "myvector contains:";

    for (vector<int>::iterator it = myvector.begin(); it!=myvector.end(); ++it)

        cout << ' ' << *it;

    cout << '\n';

    return 0;

}