There are two scenarios:

1. Using "delete this;" in destructor

Here the call will be a recursive call to the destructor 
infinitely. So the program hangs here.

2. Using "delete this;" in other members of a class 
including constructor.

In this case, the call is a sucide call since the object 
tries to delete itself which is nothing but sitting in a 
space and destroy that space itself. That is definitely a 
memory crash.