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  1. #include <iostream>
  2. #include <memory>
  3.  
  4. struct releaseable_object
  5. {
  6. 	releaseable_object() : dummy_ptr(new int) {}
  7. 	void Release()
  8. 	{
  9. 		std::cout << "Releasing releaseable object\n";
  10. 		delete dummy_ptr;
  11. 	}
  12. 	int *const dummy_ptr;
  13. };
  14.  
  15. struct A : releaseable_object {};
  16. struct B : releaseable_object {};
  17.  
  18. namespace factory
  19. {
  20. 	A *CreateA(/* lots of parameters */) { return new A; }
  21. 	B *CreateB(/* lots of parameters */) { return new B; }
  22. }
  23.  
  24. template <typename T> struct Managed
  25. {
  26. 	using type = T;
  27. 	struct deleter {
  28. 	  void operator()(T* object) {
  29. 		std::cout << "Release!\n";
  30. 		object->Release();
  31. 	  }
  32. 	};
  33. 	using pointer = std::unique_ptr<T, deleter>;
  34. };
  35.  
  36. struct ManagedA : Managed<A>
  37. {
  38. 	using base = Managed<A>;
  39. 	using base::pointer;
  40. 	ManagedA(/* lots of parameters */)
  41. 	{
  42. 		// do A specific stuff...
  43. 		A *a = factory::CreateA(/* lots of parameters */);
  44. 		// more A specific stuff...
  45.  
  46. 		// wrap the pointer:
  47. 		m_pointer.reset(a);
  48. 	}
  49. 	pointer m_pointer;
  50. };
  51.  
  52. int main()
  53. {
  54. 	std::cout << sizeof(void*) << '\n';
  55. 	std::cout << sizeof(ManagedA::pointer) << '\n';
  56. 	return 0;
  57. }
Success #stdin #stdout 0s 3296KB
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https://ideone.com/wnmk9p
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
secret

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