Return Value Optimization

RVO.cpp

#include <string>
#include <functional>
#include <iostream>
#include <optional>

class Test {
  public:
  Test() 
  {
      std::cout<<"Default Constructor\n";
  }
  Test(const Test&) 
  { 
      std::cout << "A copy constructor was called\n"; 
  }
};


Test func() 
{
  return Test();
}

int main() {
  std::cout << "Hello World!\n";
  Test obj = func();
}