Re: Exception caught inside a constructor

Hi

The following program throws an exception while allocating "A" object.
Allocation fails. An exception is caught inside "C" constructor.
"C" destructor releases memory for both objects. Segmentation fault
occurs while releasing memory for object "A" since the memory has actually not
been allocated for that object.

Please help me to modify the program to work correctly. I want all exceptions
to be caught inside a "C" constructor and no memory leak should happen.

I am aware that this problem may be solved by wrapping ptrA and ptrB in a smart
pointers but I am not interested in this solution.

Thanks for help.

#include <iostream>

using namespace std;

struct A {
  A(void)
  {
    cout << "A" << endl;
  }

  ~A(void)
  {
    cout << "~A" << endl;
  }

  void* operator new(size_t size)
  {
    cout << "A new" << endl;
    throw 10; // allocation fails
    return ::operator new(size);
  }
};

struct B {
  B(void)
  {
    cout << "B" << endl;
  }

  ~B(void)
  {
    cout << "~B" << endl;
  }
};

struct C {
  B *ptrB;
  A *ptrA;

  C(void)
  {
    cout << "C" << endl;
    try {
      ptrB = new B;
    } catch(...) {
      cout << "new B - exception" << endl;
    }
    try {
      ptrA = new A;
    } catch(...) {
      cout << "new A - exception" << endl;
    }
  }

  ~C(void) {
    cout << "~C" << endl;
    delete ptrB;
    delete ptrA;
  }
};

int main(void)
{
  try {
    C c;
  } catch(...) {
    cout << "main exception handler" << endl;
  }
}