allocates and frees an object and an array of objects of type loc. : object array « Class « C++ Tutorial

1. C++ Tutorial
2. Class
3. object array

#include <iostream>
#include <cstdlib>
#include <new>
using namespace std;
   
class loc {
  int longitude, latitude;
public:
  loc() {longitude = latitude = 0;}
  loc(int lg, int lt) {
    longitude = lg;
    latitude = lt;
  }
   
  void show() {
    cout << longitude << " ";
    cout << latitude << "\n";
  }
   
  void *operator new(size_t size);
  void operator delete(void *p);
   
  void *operator new[](size_t size);
  void operator delete[](void *p);
};
   
// new overloaded relative to loc.
void *loc::operator new(size_t size)
{
void *p;
   
  cout << "In overloaded new.\n";
  p =  malloc(size);
  if(!p) {
    bad_alloc ba;
    throw ba;
  }
  return p;
}
   
// delete overloaded relative to loc.
void loc::operator delete(void *p)
{
  cout << "In overloaded delete.\n";
  free(p);
}
   
// new overloaded for loc arrays.
void *loc::operator new[](size_t size)
{
  void *p;
   
  cout << "Using overload new[].\n";
  p =  malloc(size);
  if(!p) {
    bad_alloc ba;
    throw ba;
  }
  return p;
}
   
// delete overloaded for loc arrays.
void loc::operator delete[](void *p)
{
  cout << "Freeing array using overloaded delete[]\n";
  free(p);
}
   
int main()
{
  loc *p1, *p2;
  int i;
   
  try {
    p1 = new loc (10, 20); // allocate an object
  } catch (bad_alloc xa) {
    cout << "Allocation error for p1.\n";
    return 1;;
  }
   
  try {
    p2 = new loc [10]; // allocate an array
  } catch (bad_alloc xa) {
    cout << "Allocation error for p2.\n";
    return 1;;
  }
   
  p1->show();
 
  for(i=0; i<10; i++)
    p2[i].show();
   
  delete p1;    // free an object
  delete [] p2; // free an array
   
  return 0;
}