C++ 算法 中的 swap函数

template<class T> void swap(T& a, T& b);

#include <iostream> 
#include <algorithm>
#include <vector>   
int main () 
{
  int a=14, b=9;
  std::swap(a,b);
  std::vector<int> sg (4,a), ss (6,b);      
  std::swap(sg,ss);                          
  std::cout << "sg contains:";
  for (std::vector<int>::iterator ti=sg.begin(); ti!=sg.end(); ti++)
    std::cout << ' ' << *ti;
  std::cout << '\n';

  return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
	int ss = 9;
	int sg = 14;
	cout << "Value of ss before swapping: " << ss << endl;
	cout << "Value of sg before swapping: " << sg << endl;
	swap(ss, sg);
	cout << "Value of ss after swapping: " << ss << endl;
	cout << "Value of sg after swapping: " << sg << endl;
	return 0;
}