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  1. #include <iostream>
  2. #include <cassert>
  3. using namespace std;
  4.  
  5. struct A
  6. { virtual ~A() {} };
  7. struct B : A
  8. { virtual ~B() {} };
  9. struct C
  10. { virtual ~C() {} };
  11. struct D : B, C
  12. { virtual ~D() {} };
  13.  
  14. C *make_c0()
  15. {
  16. 	return new D;
  17. }
  18.  
  19. C *make_c1()
  20. {
  21. 	return new C;
  22. }
  23.  
  24. int main() 
  25. {
  26. 	{
  27. 		auto c = make_c0();
  28. 		auto a = dynamic_cast<A*>(c);
  29. 		if (a == nullptr) {
  30. 			cout << "A from C via D is null\n";
  31. 		}
  32. 	}
  33.  
  34. 	{
  35. 		auto c = make_c1();
  36. 		auto a = dynamic_cast<A*>(c);
  37. 		if (a == nullptr) {
  38. 			cout << "A from C without D is null\n";
  39. 		}
  40. 	}
  41.  
  42. 	// your code goes here
  43. 	return 0;
  44. }
Success #stdin #stdout 0s 3460KB
comments (?)
stdin 
Standard input is empty
stdout 
A from C without D is null
https://ideone.com/o8uNlj
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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