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3112025
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0
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0
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2
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2010-06-24T16:43:47.117
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0
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2010-06-24T17:21:59.240
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2010-06-24T17:21:59.240
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34509
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34509
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3111892
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2
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0
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0
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text
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You have to pass the class type of the derived. To not break the typedef-way, you can can give that parameter a default value. Something like the following should work <pre><code>template<typename Object, typename Data, typename Derived = void> class Callback; namespace detail { template<typename Object, typename Data, typename Derived> struct derived { typedef Derived derived_type; }; template<typename Object, typename Data> struct derived<Object, Data, void> { typedef Callback<Object, Data, void> derived_type; }; } template<typename Object, typename Data, typename Derived> class Callback : detail::derived<Object, Data, Derived> { typedef typename detail::derived<Object, Data, Derived>::derived_type derived_type; derived_type &getDerived() { return static_cast<derived_type&>(*this); } public: // ... stays unchanged ... derived_type& set(PHandler handler) { pHandler = handler; return getDerived(); } void run() { (pObj->*pHandler)(&getDerived()); } // ... stays unchanged ... }; </code></pre> <hr> Alternatively you can simply have two classes for this. One for inheritance and one if you don't inherit. The first is for inheritance <pre><code>template<typename Object, typename Data, typename Derived> class CallbackBase { typedef Derived derived_type; derived_type &getDerived() { return static_cast<derived_type&>(*this); } public: // ... stays unchanged ... derived_type& set(PHandler handler) { pHandler = handler; return getDerived(); } void run() { (pObj->*pHandler)(&getDerived()); } // ... stays unchanged ... }; </code></pre> And the second is for non-inheritance. You can make use of the base-class for this <pre><code>template<typename Object, typename Data> struct Callback : CallbackBase<Object, Data, Callback<Object, Data> > { Callback(Object* obj, PHandler handler) : Callback::CallbackBase(obj, handler) {} }; </code></pre>
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1. This table or related slice is empty.
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1. POPointer-to-member-func, template & inheritance mixup
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1. PTAnswer
UserLastEditorUserId
1. USJohannes Schaub - litb
UserOwnerUserId
1. USJohannes Schaub - litb
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1. POPointer-to-member-func, template & inheritance mixup
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1. VO
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1. COThanks, it looks like a good solution. I'll study it some more...
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 USAlex O
2. COThe stuff you put in "namespace detail" was what I was missing. Thanks.
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 USAlex O

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