fork download 
  1. #include <iostream>
  2. using namespace std;
  3.  
  4. class Base;
  5. class A;
  6. class B;
  7.  
  8. class Base {
  9. public:
  10. 	const char* type;
  11. 	int value;
  12. 	virtual bool operator==(Base&) = 0;
  13. 	virtual bool equals(A*) = 0;
  14. 	virtual bool equals(B*) = 0;
  15. protected:
  16. 	Base(){}
  17. };
  18.  
  19. class A : public Base {
  20. public:
  21. 	const char* type;
  22. 	int value;
  23. 	A(int value = 0) : type("A"), value(value) {}
  24.  
  25. 	virtual bool operator==(Base& base) {
  26. 		return base.equals(this);
  27. 	}
  28. protected:
  29. 	virtual bool equals(A* a){
  30. 		return (type == a->type && value == a->value);
  31. 	}
  32. 	virtual bool equals(B* b){
  33. 		return false;
  34. 	}
  35. };
  36. class B : public Base {
  37. public:
  38. 	const char* type;
  39. 	int value;
  40. 	B(int value = 0) : type("B"), value(value) {}
  41.  
  42. 	virtual bool operator==(Base& base) {
  43. 		return base.equals(this);
  44. 	}
  45. protected:
  46. 	virtual bool equals(A* a){
  47. 		return false;
  48. 	}
  49. 	virtual bool equals(B* b){
  50. 		return (type == b->type && value == b->value);
  51. 	}
  52. };
  53.  
  54. int main() {
  55. 	A a(5);
  56. 	A a2(5);
  57. 	B b(5);
  58. 	Base *base_a = &a;
  59. 	Base *base_a2 = &a2;
  60. 	Base *base_b = &b;
  61.  
  62. 	cout << (*base_a == *base_b) << endl;
  63. 	cout << (*base_a == *base_a2) << endl;
  64.  
  65. 	return 0;
  66. }
Success #stdin #stdout 0s 3340KB
comments (?)
stdin 
Standard input is empty
stdout 
0
1
http://ideone.com/p4T4uo
language:
C++ 4.8.1
created:
306 days ago
visibility:
public

Share or Embed source code