BAD Example of code. C++

bad_example.cpp

/*
* Learning C++ Best Practices :: Avoid Defining Any Default Operations, Or Define Them All (Jason Turner)
* https://learning.oreilly.com/videos/learning-c-best/9781491954898/9781491954898-video241545
*/

#include <string>

struct S {
  ~S() {};
  std::string s;
};

int main() {
  std::vector<S> ss;
  for (int i = 0; i < 100; ++i){
    ss.emplace_back();
  }
}

// problem: defined destructor prevents creating move constructor and move assignment operators for us. And it affects class usage performance!