Testing raw pointer deletion. Compile with `g++ -o demo -g -O0 -Wall pointer_demo.cc `

pointer_demo.cc

#include <iostream>
#include <vector>

using namespace std;

class A {

public:
  
  A(): thing(nullptr) {}
  
  void DoThing(int * x) {
    if (x != thing) {
      delete thing;
      thing = x;
    }
  }
  
  int * thing;

};

int main() {
  cout << "running demo" << endl;
  A a;
  cout << "a.thing: " << a.thing << endl;

  int * xxx = new int(3);
  a.DoThing(xxx);
  cout << "a.thing: " << a.thing << " : " << *(a.thing) << endl;
  cout << "xxx: " << xxx << " : " << *xxx << endl;
  
  int * yyy = new int(4);
  a.DoThing(yyy);
  cout << "a.thing: " << a.thing << " : " << *(a.thing) << endl;
  cout << "xxx: " << xxx << " : " << *xxx << endl;
  cout << "yyy: " << yyy << " : " << *yyy << endl;

  cout << "Trying to delete xxx:" << endl;
  if (xxx != NULL) {
    cout << "xxx is not NULL" << endl;
    delete xxx;
  }
}