c++ - What is the use of "delete this"?

Question

Today, I have seen some legacy code. In the destructor there is a statement like "delete this". I think, this call will be recursive. Why it is working?

I made some quick search on Y!, I found that if there is a need to restrict the user to create the stack object, we can make destructor private and provide an interface to delete the instance. In the interface provided, we have to call delete on this pointer.

Are there any other situations for using such statements?

Answer 1

"delete this" is commonly used for ref counted objects. For a ref counted object the decision of when to delete is usually placed on the object itself. Here is an example of what a Release method would look like [1].

int MyRefCountedObject::Release() {
  _refCount--;
  if ( 0 == _refCount ) {
    delete this;
    return 0;
  }
  return _refCount;
}

ATL COM objects are a prime example of this pattern.

[1] Yes I realize this is not thread safe.