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  1. 	#include <iostream>
  2.  
  3. 	using namespace std;
  4.  
  5. 	struct A {
  6. 		int a[64];
  7. 		A() { cout << "A()" << endl; }
  8. 		A(const A&) { cout << "A(A&)" << endl; }
  9. 		A& operator = (const A&) { cout << "A=A" << endl; return *this; }
  10. 	};
  11.  
  12. 	struct B : virtual public A {
  13. 		int b[64];
  14. 		B() { cout << "B()" << endl; }
  15. 		B(const B&) { cout << "B(B&)" << endl; }
  16. 		B(const A&) { cout << "B(A&)" << endl; }
  17. 		B& operator = (const B&) { cout << "B=B" << endl; return *this; }
  18. 		B& operator = (const A&) { cout << "B=A" << endl; return *this; }
  19. 	};
  20.  
  21. 	struct C : virtual public A {
  22. 		int c[64];
  23. 		C() { cout << "C()" << endl; }
  24. 		C(const C&) { cout << "C(C&)" << endl; }
  25. 		C(const B&) { cout << "C(B&)" << endl; }
  26. 		C(const A&) { cout << "C(A&)" << endl; }
  27. 		C& operator = (const C&) { cout << "C=C" << endl; return *this; }
  28. 		C& operator = (const B&) { cout << "C=B" << endl; return *this; }
  29. 		C& operator = (const A&) { cout << "C=A" << endl; return *this; }
  30. 	};
  31.  
  32. 	struct END : virtual public B, C {
  33. 		int end[64];
  34. 		END() { cout << "END()" << endl; }
  35. 		END(const END&) { cout << "END(END&)" << endl; }
  36. 		END(const C&) { cout << "END(C&)" << endl; }
  37. 		END(const B&) { cout << "END(B&)" << endl; }
  38. 		END(const A&) { cout << "END(A&)" << endl; }
  39. 		END& operator = (const END&) { cout << "END=END" << endl; return *this; }
  40. 		END& operator = (const C&) { cout << "END=C" << endl; return *this; }
  41. 		END& operator = (const B&) { cout << "END=B" << endl; return *this; }
  42. 		END& operator = (const A&) { cout << "END=A" << endl; return *this; }
  43. 	};
  44.  
  45. 	int main() {
  46. 		END* end = new END();
  47.  
  48. 		A *a = dynamic_cast<A*>(end);
  49. 		B *b = dynamic_cast<B*>(end);
  50. 		C *c = dynamic_cast<C*>(end);
  51.  
  52. 		std::cout << "end = " << (void*)end << std::endl;
  53. 		std::cout << "a = " << (void*)a << std::endl;
  54. 		std::cout << "b = " << (void*)b << std::endl;
  55. 		std::cout << "c = " << (void*)c << std::endl;
  56.  
  57. 		// the direct pointers are going to have to differ
  58. 		// to point to the correct vtable. what about 'a' in all cases?
  59. 		std::cout << "end->a = " << (void*)&(end->a) << std::endl;
  60. 		std::cout << "a->a = " << (void*)&(a->a) << std::endl;
  61. 		std::cout << "b->a = " << (void*)&(b->a) << std::endl;
  62. 		std::cout << "c->a = " << (void*)&(c->a) << std::endl;
  63.  
  64.  
  65. 	}
  66.  
Success #stdin #stdout 0s 3432KB
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stdin
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Standard input is empty
stdout
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A()
B()
C()
END()
end = 0x823a008
a = 0x823a310
b = 0x823a20c
c = 0x823a008
end->a = 0x823a310
a->a = 0x823a310
b->a = 0x823a310
c->a = 0x823a310
https://ideone.com/0QAoWE
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
secret

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