Internal delegate and Stack Overflow

[tsalm]

Hello,

I would do something like this, but this return me an execution error :
object.Exception: Stack Overflow

// --------CODE--------
class A
{
  void delegate() dg;

  void doIt()
  {
   dg();
  }
}

class B
{
  A a;

  this()
  {
   a = new A;
   a.dg = { doSomething(); };
  }

  void doSomething() { }
}

void main()
{
  auto b = new B;
  b.a.doIt();
}
// ------END CODE------

Is this a bug or have I do something wrong ?
Thanks in advance for your help,
TSalm