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  1. #include <iostream>
  2.  
  3. template <class Dest, class Src>
  4. Dest force_cast(Src src)
  5. {
  6. 	union
  7. 	{
  8. 		Dest d;
  9. 		Src s;
  10. 	} convertor;
  11. 	convertor.s = src;
  12. 	return convertor.d;
  13. }
  14.  
  15. class ABase {
  16. 	virtual void bind() = 0;
  17. };
  18.  
  19. class B;
  20.  
  21. class A
  22.   : public ABase {
  23. public:
  24. 	// int a, b;
  25.  
  26. 	class Unknown{};
  27. 	typedef int(A::*Function)();
  28.  
  29. 	void bindFunction(void* f) { 
  30. 		this->f = force_cast<Function>(f);	
  31. 	}
  32.  
  33. 	int call() {
  34. 		return (this->*f)();
  35. 	}
  36.  
  37. 	Function f;
  38. };
  39.  
  40. class B {
  41. private: 
  42. 	int answer;
  43. public:
  44. 	B(int value) : answer(value) {}
  45.  
  46. 	// int c, d;
  47. 	int getValue() { return answer; }
  48. };
  49.  
  50. class Combined
  51.  : public A, public B {
  52. public: 	
  53. 	Combined(int value) : B(value), A() {}
  54.  
  55. 	virtual void /*A::*/bind() /* override */ {
  56. 		A::bindFunction( force_cast<void*>( &Combined::getValue ) );
  57. 	}
  58. };
  59.  
  60. int main() {
  61. 	Combined c(42);
  62. 	c.bind();
  63. 	std::cout << "The answer to Life, The Universe and Everything is " << c.call() << "\n";
  64. 	return 0;
  65. }
Success #stdin #stdout 0.01s 16064KB
comments (?)
stdin 
Standard input is empty
stdout 
The answer to Life, The Universe and Everything is 1991543360
https://ideone.com/daHHcL
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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