pure virtual class

[Prawit Chaivong]

Hi, gurus

The Ctor & Dtor of pure virtual class (interface class) should be

IMyClass() = 0;
or
IMyClass() { }

Thank in advance

Prawit C.

[Victor Bazarov]

Prawit Chaivong wrote:

The Ctor & Dtor of pure virtual class (interface class) should be

IMyClass() = 0;
or
IMyClass() { }

First of all, there is no such thing as "pure virtual class". There is
an 'abstract class', maybe you meant to use that term? I'll assume so.
To answer what I think was your question, (a) you cannot make a c-tor
pure by adding "=0" to it because c-tors cannot be virtual and only the
virtual members can be declared pure, and (b) as to the d-tor, it's up
to you, but remember that even if you do declare the d-tor pure, you still
need to provide an [empty] implementation, since it's definitely going to
be called.

V

[BigBrian]

> Hi, gurus

The Ctor & Dtor of pure virtual class (interface class) should be

IMyClass() = 0;
or
IMyClass() { }

Thank in advance

Prawit C.

Homework?

You could at least search the newsgroup to determine the answer for
yourself. Also, maybe you should read your text book.

[Peter Julian]

"Prawit Chaivong" <pr******@gmail.com> wrote in message
news:11*********************@g43g2000cwa.googlegro ups.com...

Hi, gurus

The Ctor & Dtor of pure virtual class (interface class) should be

IMyClass() = 0;
or
IMyClass() { }

Thank in advance

Prawit C.

An abstract class's ctor and dtor can't be pure-virtual. The logic is
simple: a derived class can't overide / overload base class ctor(s) or
d~tor. This is true whether the base is abstract or not.

Now you know why you can't "call", but only "invoke", a base ctor or d~tor.

[Victor Bazarov]

Peter Julian wrote:

"Prawit Chaivong" <pr******@gmail.com> wrote in message
news:11*********************@g43g2000cwa.googlegro ups.com...

Hi, gurus

The Ctor & Dtor of pure virtual class (interface class) should be

IMyClass() = 0;
or
IMyClass() { }

Thank in advance

Prawit C.

An abstract class's ctor and dtor can't be pure-virtual. The logic is
simple: a derived class can't overide / overload base class ctor(s) or
d~tor. This is true whether the base is abstract or not.

Now you know why you can't "call", but only "invoke", a base ctor or d~tor.

I can call the d-tor without any problem. I can even call it for
an int or a double. Didn't you know?

V