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 TechnicalTalk » Programming and Web Development » C/C++
 Overloading New and Delete operators in C++

[nikon]

nikon  

 Overloading New and Delete operators in C++

Hello All

I want to overload new and delete operator using c++, I have tried it lot but unable to get any success. have you ever done it ? If yes please give me some hint about it.

[jaincool]

jaincool  

 Re: Overloading New and Delete operators in C++

There is nothing much difficult in Overloading new and delete operator................

Here is a short tutorial on it.......

Code:

#include <iostream.h>
#include <cstdlib.h>
#include <new>
Class loc {
                int longitude,latitude;
    public:
              loc{}
              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 *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;
      }


Void loc:;operator delete(void *p)
{
   cout << “in overloaded delete “;
   free(p);
}


Int main()
   {
       loc *p1,*p2;
  try {      p1=new loc(10,20);  }
  catch(bad_alloc xa) {
         cout<<“Allocation error for p1\n”;
          return 1;             }

 try {  p2=new loc(-10,-20);  }
  catch (bad_alloc xa) {
cout<<“Allocation error for p1\n”;
         return 1;              }

p1->show();
p2->show();
delete p1;
delete p2;

return 0;
}

[msdnguide]

msdnguide  

 Re: Overloading New and Delete operators in C++

jaincool has given perfect example.  It works this way

[john14317]

john14317  

 Re: Overloading New and Delete operators in C++

check the simple example .......

Code:

class Myclass
{
public:
        void* operator new(size_t);
        void operator delete(void*);
};

void* Myclass::operator new(size_t size)
{
    void *storage = malloc(size);
    if(NULL == storage) {
            throw "allocation fail : no free memory";
    }
}

[kellylsn]

kellylsn  

 Re: Overloading New and Delete operators in C++

[Payday Loan]

We can't overload new and delete operators.

[dianna]

dianna  

 Re: Overloading New and Delete operators in C++

Operators
The new operator throws std::bad_alloc, when the allocation fails.

Code:

namespace std
{
    class bad_alloc : public exception { /* ... */ };
}
// normal new and delete throws bad_alloc
void* operator new(size_t)    throw(bad_alloc);
void  operator delete(void *) throw();