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  1. #include <list>
  2. #include <utility>
  3. #include <iostream>
  4.  
  5.  
  6. class Base
  7. {
  8. public:
  9. 	void doForAllDerived()
  10. 	{
  11. 		for (handlerList_t::const_iterator it = _registeredHandlers.begin(); it != _registeredHandlers.end(); ++it )
  12. 			(it->second)( it->first, 5 );
  13. 	}
  14.  
  15. protected:
  16.     typedef void(*PrepFn)(Base*, int);
  17.     typedef std::pair< Base *, PrepFn > handlerPair_t;
  18.     void registerPrepFn( PrepFn fn, Base * instance )
  19.     {
  20.         _registeredHandlers.push_back( handlerPair_t( instance, fn ) );
  21.     };
  22.  
  23. private:
  24.     typedef std::list< handlerPair_t > handlerList_t;
  25.     handlerList_t _registeredHandlers;
  26. };
  27.  
  28. class Derived : public Base
  29. {
  30. public:
  31.     Derived() {
  32.         registerPrepFn( &Derived::derivedPrepFn, this );
  33.     };
  34.  
  35. protected:
  36.     static void derivedPrepFn( Base* b_ptr, int n )
  37.     {
  38.         Derived * p_d = static_cast<Derived *>( b_ptr );
  39.         p_d->realHandler( n );
  40.     };
  41.  
  42.     void realHandler( int n ) { std::cout << n << std::endl;};
  43.  
  44. };
  45.  
  46. int main() {
  47.     Derived anInstance;
  48.     anInstance.doForAllDerived();
  49. }
  50.  
Success #stdin #stdout 0.02s 2856KB
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5
https://ideone.com/2LdQz
language:
C++ (gcc 8.3)
created:
13 years ago
visibility:
public

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