Re: functionpointers to another class

From:

James Kanze <james.kanze@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Tue, 7 Oct 2008 04:46:47 -0700 (PDT)

Message-ID:

<0378d338-8144-40f2-b204-8631d7b37656@v28g2000hsv.googlegroups.com>

On Oct 7, 10:21 am, "A.Gallus" <u...@rz.uni-karlsruhe.de> wrote:

I want to define a functor which calls methods of other classes via a
function pointer:

class play
{
public:
    void operator ()
    {
        (*this.*fp)();
    }

private:
    void (OtherClass::*fp) ();
};

Is this possible somehow?

Of course. You're on the right track, the only thing is in the
operator()():

1. You need an object of type OtherClass (or a pointer to such
    an object); you can't use a pointer to a member of
    OtherClass with this (which is a pointer to play).

2. Your syntax isn't quite right for the call. If you have a
    pointer, then it would be (otherObject->*fp)() if you have
    a reference or an object, (otherObject.*fp)().

3. And also, it should be operator()().

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