C++如何将一个vector内容赋值给另一个vector,及swap与assign区别

vector<int> v2;
v2.push_back(0);
v2.push_back(1);
vector<int> v1(v2); //声明

vector<int> v2;
v2.push_back(0);
v2.push_back(1);
vector<int> v1; //声明v1
v1.assign(v2.begin(), v2.end());//将v2赋值给v1

vector<int> v2;
v2.push_back(0);
v2.push_back(1);
vector<int> v1();
v1.swap(v2); //将v2赋值给v1

vector<int> v2;
v2.push_back(0);
v2.push_back(1);
vector<int> v1;
vector<int>::iterator it;//声明迭代器
for(it = v2.begin(); it!=v2.end(); ++it)//遍历v2,赋值给v1
{
	v1.push_back(it);
}

vector<int> v2;
v2.push_back(0);
v2.push_back(1);
vector<int> v1;
v1 = v2;

//引用方式传参
int testFun1(vector<int> &v1)
{
	vector<int> v2;
	v2.push_back(0);
	v2.push_back(1);
	v1 = v2;
}
//指针方式传参
int testFun2(vector<int> *v1)
{
	vector<int> v2;
	v2.push_back(0);
	v2.push_back(1);
	v1 = &v2;
}
//全局或者局部变量方式
vector<int> v2;
int testFun2(vector<int> v1)
{
	v2.push_back(0);
	v2.push_back(1);
	v1 = v2;
}
int testFun2()
{
	//方式一
	vector<int> v1;
	testFun1(&v1);
	//方式二
	vector<int> *v2;
	testFun1(v2);
	//方式三
	vector<int> v3;
	testFun1(v3);
}

#include <vector>
#include "DebugUtility.h"
#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
void print(int x)
{
    cout << x << endl;
}
void Swap(vector<string>& source, vector<string>& dest)
{
    DebugUtility temp;
    dest.swap(source);
}
void Assign(vector<string>& source, vector<string>& dest)
{
    DebugUtility temp; 
    dest.assign(source.begin(), source.end());
}
int main(int argc, const char *argv[])
{
    vector<string> source(900000, "90");
    vector<string> destination(1, "abc");
    Swap(source, destination);
    //source.clear();
    //for_each(destination.begin(), destination.end(), print);
    //Assign(source, destination);
    //source.clear();
    //for_each(destination.begin(), destination.end(), print);
    return 0;
}