invoking destructor from within instance method

[Fred]

Is it legal to invoke my destructor from within an instance function?

For example,
bool MyClass::someFu nction() {
SomeOtherClass: someFunction(th is);
// No other references to 'this'
// after this point
return true;
}

SomeOtherClass: :someFunction(M yClass m) {
delete m;
}

--
Fred Kleinschmidt

[Andy Champ]

Fred wrote:

Is it legal to invoke my destructor from within an instance function?

For example,
bool MyClass::someFu nction() {
SomeOtherClass: someFunction(th is);
// No other references to 'this'
// after this point
return true;
}

SomeOtherClass: :someFunction(M yClass m) {
delete m;
}

It's legal. We use this with smart pointers.

When the reference count for the object goes to zero, the object deletes
itself. If I can get the syntax right...

void smartTarget::re lease()
{
if (--refcount == 0)
delete this;
}

smartPointer::~ smartPointer
{
m_Target->release();
}

Looks odd I admit, and you'd better not access any class data after the
delete!

Andy

[Joshua]

On Jun 3, 6:01 am, Fred <fred.l.kleinsc [e-mail] mwrote:

Is it legal to invoke my destructor from within an instance function?

For example,
bool MyClass::someFu nction() {
SomeOtherClass: someFunction(th is);
// No other references to 'this'
// after this point
return true;

}

SomeOtherClass: :someFunction(M yClass m) {
delete m;

}

--
Fred Kleinschmidt

Unsafe.

Myclass m;
m.someFunction( ); // delete variable on stack!

[Victor Bazarov]

Joshua wrote:

On Jun 3, 6:01 am, Fred <fred.l.kleinsc [e-mail] mwrote:

>Is it legal to invoke my destructor from within an instance function?

For example,
bool MyClass::someFu nction() {
SomeOtherClass: someFunction(th is);
// No other references to 'this'
// after this point
return true;

}

SomeOtherClass ::someFunction( MyClass m) {
delete m;

}

--
Fred Kleinschmidt

Unsafe.

Myclass m;
m.someFunction( ); // delete variable on stack!

Nothing in the original post says that the class *isn't* designed
to be only allocated using 'new' (the common approach with some
COM and CORBA objects, I'm told).

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

[James Kanze]

On Jun 3, 12:01 am, Fred <fred.l.kleinsc [e-mail] mwrote:

Is it legal to invoke my destructor from within an instance function?

Of course not. It's probably the most common case, in fact.

For example,
bool MyClass::someFu nction() {
SomeOtherClass: someFunction(th is);
// No other references to 'this'
// after this point
return true;
}

SomeOtherClass: :someFunction(M yClass m) {

The parameter should be a pointer, of course.

delete m;
}

I'm not too sure I like the added indirection. Most of the
time (something slightly over half), deletion is done by "delete
this".

--
James Kanze (GABI Software) email:ja******* **@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientier ter Datenverarbeitu ng
9 place Sémard, 78210 St.-Cyr-l'École, France, [phone]

[James Kanze]

On Jun 3, 3:40 am, Joshua <zhou.zhihua.m. [e-mail] te:

On Jun 3, 6:01 am, Fred <fred.l.kleinsc [e-mail] mwrote:

Is it legal to invoke my destructor from within an instance
function?

For example,
bool MyClass::someFu nction() {
SomeOtherClass: someFunction(th is);
// No other references to 'this'
// after this point
return true;
}

SomeOtherClass: :someFunction(M yClass m) {
delete m;
}

Unsafe.

No more dangerous than anything else.

Myclass m;
m.someFunction( ); // delete variable on stack!

And how does the fact that someFunction() is a member change
anything. If the object has value semantics, no one should
delete it, since it shouldn't be allocated dynamically. And if
it has identity, all instances will be allocated dynamically,
and deletion will be in response to some external event. If the
event is processed by the object itself, then the object
deletes itself; if the event is processed by some other object,
then that object deletes the object. Obviously, there are other
kinds of objects as well, but these two represent well over 90%
of the objects in a typical simple application.

--
James Kanze (GABI Software) email:ja******* **@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientier ter Datenverarbeitu ng
9 place Sémard, 78210 St.-Cyr-l'École, France, [phone]

[sumsin]

On Jun 3, 3:01 am, Fred <fred.l.kleinsc [e-mail] mwrote:

Is it legal to invoke my destructor from within an instance function?

For example,
bool MyClass::someFu nction() {
SomeOtherClass: someFunction(th is);
// No other references to 'this'
// after this point
return true;

}

SomeOtherClass: :someFunction(M yClass m) {
delete m;

}

It should be like:
SomeOtherClass: :someFunction(M yClass *m) {
delete m;
}

because you are passing a pointer.

>

Though its legal but its not safe.

Functions are made to call. Though there is no reference of 'this'
pointer after deleting it in some other class's member function, but
the caller who is calling the 'someFunction' of 'MyClass' (of course
through some MyClass variable) doesn't know about this deletion and
think what will happen if he try to access some other property of
MyClass?