#include <iostream>
 #include <utility>
 #include <vector>


 template <typename T>
 void swap(T& a, T& b){
     T tmp(std::move(a));
     a = std::move(b);
     b = std::move(tmp);
 }

 struct MyData{
   std::vector<int> myData;

   MyData():myData({1,2,3,4,5}){}

   // copy constructor
   MyData(const MyData& m):myData(m.myData){
     std::cout << "copy constructor"  << std::endl;
   }

   // copy assignment operator
   MyData& operator=(const MyData& m){
     myData= m.myData;
     std::cout << "copy assignment operator"  << std::endl;
     return *this;
   }

 };

 int main(){

   std::cout << std::endl;

   MyData a,b;
   swap(a,b);

   std::cout << std::endl;

 };