class CClass
{
public:
int* pRandomData;
char chOtherRandomData;
CClass()
{
// Set any kind of pointers to data that might be allocated to NULL on initialization
// You do that in case the data is never allocated
pRandomData = NULL;
}
~CClass()
{
// Now you check to see if the data is allocated
if( pRandomData )
// It must point to valid data, because we set it to NULL every time it doesnt
delete [] pRandomData; // Delete it
// Set the pointer to NULL now, so we know it doesnt contain any data
pRandomData = NULL;
}
void Allocate()
{
// Allocate our memory - pRandomData now points to valid data
// In reality, you should probably make sure that the data hasnt already been allocated
// with a null check
pRandomData = new int[100];
}
};
void Usage()
{
// Allocate pObject
CClass* pObject = new CClass();
// pObject is now valid data
pObject->Allocate(); // Allocate the random data
// Delete it, and it will all be deallocated
delete pObject;
// Now allocate pObject again
pObject = new CClass();
// But this time, we wont allocate the random data before we delete
delete pObject;
// What happens? Nothing! Because we set pRandomData to NULL at init, our destructor knew not to delete it
// Tada!
}
