Re: Multiple inheritance
On Dec 10, 11:25 pm, "Andrew Wall" <wallguide-usen...@yahoo.com>
wrote:
"beemaster" <beemast...@gmail.com> wrote in message
news:c3c6f1f5-d866-47e7-a018-b10b339ce3ad@r40g2000yqn.googlegroups.com...
I have hierarchy, that contains one base interface class -
IConnection,
and two derived interfaces: IClientConnection and IServerConnection
=================
class IConnection
{
public:
virtual void Send() = 0;
};
class IClientConnection : public virtual IConnection
{
public:
virtual void Connect() = 0;
};
class IServerConnection : public virtual IConnection
{
public:
virtual void Accept() = 0;
};
=================
I also have a realization for base interface
=================
class Connection : public virtual IConnection
{
public:
virtual void Send()
{
//...
};
};
=================
For two other interfaces I want to use existing realization of base
interface.
=================
class ServerConnection : public IServerConnection,
piblic Connection
{
public:
virtual void Accept();
};
=================
I inherit Connection, because I don't want to duplicate the code from
Connection::Send();
When I compile this code with Microsoft compiler, I get following
errors:
warning C4250: 'ClientConnection' : inherits
'Connection::Connection::Send' via dominance.
Is there a better way of doing this? How can I avoid multiple
inheritance and code duplication?
I really like an idea of such inheritance. Why is it bad?
From the source code you supply, I think you've got the hang of this
multiple inheritance thing.
The Microsoft warning C4250 is only a warning and not even that - its really
just information which you knew anyway. When I've encountered this, I've
just disabled the warning (after a lot of thought about it), and I recommend
you do the same.
IMHO this is exactly the way to use multiple inheritance - it avoids code
duplication, but you have to accept fixed compile time and run time
behaviour.
Andrew Wall
I encountered the same problem today. But I got rid of the warning by
making the base class functions as "virtual". The rationale behind
that was: if the derived class needs to add some more functionality
(in the future) than whats derived from the base, then this should
allow it to do.
But I wonder whether its a good practice or is it the correct way of
doing?
Cheers,
Anand.
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