Demonstrate overloaded new and delete. : New Delete « Overload « C++

1. C++
2. Overload
3. New Delete

Demonstrate overloaded new and delete.

 


#include <iostream>
#include <new>
#include <cstdlib>
using namespace std;

class MyClass {
  int x, y, z; 
public:
  MyClass() {
    x = y = z = 0;
    cout << "Constructing 0, 0, 0\n";
  }
  MyClass(int i, int j, int k) {
    x = i; 
    y = j; 
    z = k;
    cout << "Constructing " << i << ", ";
    cout << j << ", " << k;
    cout << '\n';
  }
  ~MyClass( ) { 
     cout << "Destructing\n"; 
  }
  void *operator new(size_t size);
  void *operator new[](size_t size);
  void operator delete(void *p);
  void operator delete[](void *p);
  void show() ;
};

void *MyClass::operator new(size_t size)
{
  void *p;

  cout << "Allocating MyClass object.\n";
  p = malloc(size);

  if(!p) {
    bad_alloc ba;
    throw ba;
  }
  return p;
}

void *MyClass::operator new[](size_t size)
{
  void *p;

  cout << "Allocating array of MyClass objects.\n";

  p = malloc(size);
  if(!p) {
    bad_alloc ba;
    throw ba;
  }
  return p;
}

void MyClass::operator delete(void *p)
{
  cout << "Deleting MyClass object.\n";
  free(p);
}

void MyClass::operator delete[](void *p)
{
  cout << "Deleting array of MyClass objects.\n";
  free(p);
}

void MyClass::show()
{
  cout << x << ", ";
  cout << y << ", ";
  cout << z << endl;
}

int main()
{
  MyClass *objectPointer1, *objectPointer2;

  try {
    objectPointer1 = new MyClass[3];       // allocate array
    objectPointer2 = new MyClass(5, 6, 7); // allocate object
  } catch (bad_alloc ba) {
    cout << "Allocation error.\n";
    return 1;
  }

  objectPointer1[1].show();
  objectPointer2->show();

  delete [] objectPointer1; // delete array
  delete objectPointer2;    // delete object

  return 0;
}

           
         
  

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