C++中的swap交换两个变量的值

用函数不用担心精度的损失

#include<iostream>
using namespace std;
int main()
{
  float a = 3.123456,b = 1234567.000000;
  swap(a,b);
  cout<<fixed;
  cout<<a<<"->"<<b<<endl;
  return 0;
}

  #include<iostream>
  #include<string>
  using namespace std;
  int main()
  {
      string a ="666",b = "999";
      swap(a,b);
      cout<<a<<"->"<<b<<endl;
      return 0;
 }