Re: multiple inheritance, name collision in base classes

From:

James Kanze <james.kanze@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Thu, 29 Jan 2009 00:25:48 -0800 (PST)

Message-ID:

<dfd7cb8a-fc8a-4a1c-8c6d-5521b7d16c6c@v18g2000pro.googlegroups.com>

On Jan 28, 3:36 pm, JenC <jcarl...@gmail.com> wrote:

I have a problem regarding multiple inheritance and name
collision in the base classes.
The problem looks like:

class BaseA
{
...
public:
    virtual unsigned int Run();
...
}

class BaseB //note, BaseB is an abstract class
{
...
public:
    virtual customType Run() = 0;
...
}

class Derived: public BaseA, public BaseB
{
...
public:
    virtual customType Run(); //only need to implement/override
BaseB's Run()
}

The problem is that both base classes have a function
Run(void) differing only in their return types, and hence I
get a compilation error. Is there a way that I can specify
that in class Derived I am overriding BaseB's Run() method?

Not directly.

Changing the functions signature of BaseB::Run() is a last
resort option (BaseA cannot be changed), but it will affect a
large amount of code, so I would rather find a different less
invasive solution. Any ideas??

The classical solution is to introduce an intermediate class
which "renames" the function:

    class BaseB2 : public BaseB
    {
    public:
        virtual customType Run()
        {
            return doRun() ;
        }

        virtual customType doRun() = 0 ;
    } ;

    class Derived : public BaseA, public BaseB2
    {
    public:
        virtual customType doRun() ;
    } ;

--
James Kanze (GABI Software) email:james.kanze@gmail.com
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