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I want to implement a class that uses boost::signal for callbacks. Other objects can register their callback functions using AddHandler() and RemoveHandler() methods.

In one SO answer it is suggested that we track the boost::signal::connection objects returned from connect(), but in another it is suggested that we don't! I'm not clear on how to manage the connections.

How would I be able to look up which connection to disconnect later when I only have the slot_type?

class MyClass {
public:
    typedef void Handler();
    void AddHandler(const boost::signal<Handler>::slot_type& aHandler) {
        mSignal.connect(aHandler);
    }
    void RemoveHandler(const boost::signal<Handler>::slot_type& aHandler) {
        mSignal.disconnect(aHandler); // compiler error!
    }
private:
    boost::signal<Handler> mSignal;
};

I want a caller to be able to do something like:

MyObject lMyObject;
lMySignaler.AddHandler(boost::bind(&MyObject::OnEvent, lMyObject));
...
lMySignaler.RemoveHandler(boost::bind(&MyObject::OnEvent, lMyObject));
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sourcenouveau
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1 Answers1

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Rather than using const boost::signal<Handler>::slot_type& as my parameter type, I changed them to function pointers. Then I used the function pointers as the keys in a std::map to track the boost::signals::connections. When the RemoveHandler is called I just called disconnect on the connection and erase the entry in the map.

sourcenouveau
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