how to use object of structure with constructure in another structure?

Question

I have a structure with two constructor that has a byte* member as following :

struct structA
{
   byte* pData;  int nLength;

  structA()
  {
    pData = NULL; nLength = 0;
  }

  structA(int nLen)
  {
    pData = new byte[nLen];  nLength = nLen;
  }

  ~structA()
  {
    delete[] pData;
  }
}

Another structure namely structB has a list of structA:

struct structB
{
  CList <structA, structA&> AList;
}

Now i create an object of structA with parameter 10 as input and add it to an object of structB:

//start of scope

structA osA(10);
structB osB;
osB.AList.AddTail(osA);

//end of scope

The problem is that when the program exit from the scope, destructure of structA is called 2 times and program crashes.

what is the problem and why it occurs? any help is apperciated

Possible duplicate of http://stackoverflow.com/questions/4172722/what-is-the-rule-of-three — n. m. could be an AI, Dec 19 '15 at 12:59

score 0 · Answer 1 · answered Dec 19 '15 at 12:56

0

You need a copy constructor (or a move constructor). The compiler default copy constructor will just copy the pointer, and then both objects will delete the same pointer when you exit.

answered Dec 19 '15 at 12:56

Martin Bonner supports Monica

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what's the copy constructure? – javad Dec 19 '15 at 13:14
Google "copy constructor" or read your textbook (or buy a textbook if you don't have one). It's not something that's really suitable for a SO answer. – Martin Bonner supports Monica Dec 19 '15 at 13:16

how to use object of structure with constructure in another structure?

1 Answers1