Re: Destructors & Class Inheritance

From:

Ulrich Eckhardt <eckhardt@satorlaser.com>

Newsgroups:

microsoft.public.vc.language

Date:

Wed, 26 Apr 2006 14:47:05 +0200

Message-ID:

<9n64i3-07j.ln1@satorlaser.homedns.org>

dranger003@gmail.com wrote:

I have made a small test program with 3 objects inherited from each
other: ObjC inherited from ObjB which is inherited from ObjA. If I
create a new ObjC and I delete it, the destructors are called in the
opposite way the constructors were called:

Create ObjC
ObjA constructor
ObjB constructor
ObjC constructor
Delete ObjC
ObjC destructor
ObjB destructor
ObjA destructor

This is correct and how it should always be.

If I call "delete this" (or delete ObjC from another thread) while in
ObjC::~ObjC for example, ObjB::~ObjB & ObjA::~ObjA are never going to
get a chance to execute...

While you are in ObjC::~ObjC, you absolutely must not call delete this,
because the object is already being destroyed. Was that really what you
wanted to ask?

Other than that, if you want to invoke "delete this;" from somewhere inside
ObjA, you need a virtual destructor so that the most derived's dtor is
invoked (which then in turn invokes the base class' dtor like above).

Uli