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    <p><strong>Massive Edit</strong></p> <p>I think I got what you want, based on some heavy type-casting.</p> <p>Note that I do <strong>NOT</strong> recommend this technique. Although my example works, I believe there are some big pitfalls here that could really screw things up.</p> <p>As before, Class <code>A</code> can accept both a method of the proper signature and an object (of type <code>B</code>, or derived from type <code>B</code>, such as your <code>C</code> classes), and call the specified method on the specified object.</p> <p>Class <code>B</code> does not actually have any methods at all, and only acts as a common base-class for the two classes <code>C1</code> &amp; <code>C2</code>.</p> <p>At the bottom is a <code>main</code> that demonstrates how this is used. I left out the implementation of the two <code>SetCallback***</code> methods, as they're trivial.</p> <pre><code>class B { public: // Has nothing, only serves as base-class for C1 and C2. }; class C1: public B { public: bool DoThis(int x) const { return true; } }; class C2: public B { public: bool DoThat(int x) const { return false; } }; class A { private: bool (B::*m_check)(int) const; B* m_Obj; public: void SetCallbackFunction(bool (B::*fnc)(int) const) { m_check = fnc; } void SetCallbackObject(B* pB) { m_Obj = pB; } bool InvokeCallback(int val) { return (m_Obj-&gt;*m_check)(val); } }; int _tmain(int argc, _TCHAR* argv[]) { A a; C1 c; bool (C1::*func)(int) const; bool (B::*b_func)(int) const; func = &amp;C1::DoThis; b_func = (bool (B::*)(int) const)(func); // Dangerous Typecasting. Use caution! a.SetCallbackFunction(b_func); a.SetCallbackObject((B*)(&amp;c)); // A simpler, safer typecast. a.InvokeCallback(5); // Ends up calling C1::DoThis. _getch(); return 0; } </code></pre>
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    1. COThat is a fine and very clean solution, but there is a final step missing: what if I have C derived from B where another function matching B::m_check signature is present? The SetCallbackFunction won't let me bind to C:: functions. Could you integrate your code to clarify how I should do this? (and maybe add the SetCallbackFunction and SetCallbackObject, even if are trivial, for other readers' sake) Thanks a lot for the effort!
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    2. COI'm sorry, now I got it: I missed making B's methods virtual. Could you integrate the changes above to have the example fully answer my question?
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    3. COThere is still an open point here: the C classes will have their own distinct methods, sharing only the signature. Since they do not have to implement the methods that they do not care about, the B interface has to provide empty implementations for all its virtual methods. This smells a bit. Could something be done around this issue?
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