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copied!<p><code>IEventListener::messageArrived</code> is overloaded, so the compiler can't determine the type of <code>&IEventListener::messageArrived</code>. It could be <code>void (IEventListener::*)(Message*)</code> or <code>void (IEventListener::*)(ClientHandle*, Message*)</code>.</p> <p>The straighforward (and ugly) solution is to explicitely cast <code>&IEventListener::messageArrived</code> to the desired type at the call site, like this:</p> <pre><code>emit(static_cast<void (IEventListener::*)(Message*)>(&IEventListener::messageArrived), a_message_ptr); </code></pre> <p>or by assigning to a variable of the desired function type:</p> <pre><code>void (IEventListener::*func_ptr)(Message*) = &IEventListener::messageArrived; emit(func_ptr, a_message_ptr); </code></pre> <p>(Did I say it was ugly?)</p> <p>The template parameter could also be explicitly specified:</p> <pre><code>emit<void (IEventListener::*)(Message*)>(&IEventListener::messageArrived, a_message_ptr); </code></pre> <p>(Still ugly)</p> <p>Another imperfect solution is to deduce the type of <code>Signal</code> from the type of the listener (<code>T</code>) and the other parameters:</p> <pre><code>// Warning: untested. // For illustration purposes only template<class T> class ActionListener { public: //... void emit(void (T::*signal)()); template<class Arg1T> void emit(void (T::*signal)(Arg1T), Arg1T); template<class Arg1T, class Arg2T> void emit(void (T::*signal)(Arg1T, Arg2T), Arg1T, Arg2T); }; </code></pre> <p>This is imperfect though because the arguments types must match exactly.</p> <p>Depending how much change you can make in the design, a simpler solution would be to remove the ambiguity by giving different names to the members of IEventListener. You could also use an already existing signals/slots library, like <a href="http://www.boost.org/doc/libs/1_40_0/doc/html/signals2.html" rel="nofollow noreferrer">Boost.Signals2</a></p>

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