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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. class unsafe_func
  5. {
  6. public:
  7. 	template<class F>
  8. 	explicit unsafe_func(F f) : pd(new detail_impl<F>(f)) {
  9. 	}
  10.  
  11. 	~unsafe_func() {
  12. 		delete pd;
  13. 	}
  14.  
  15. 	template<class R, class ... Args>
  16. 	R call(Args ... args) const {
  17. 		return static_cast< detail_impl<R(*)(Args ...)>* >(pd)->f_(args...);
  18. 	}
  19.  
  20. private:
  21. 	unsafe_func(unsafe_func const &);
  22. 	unsafe_func& operator=(unsafe_func const &);
  23.  
  24. 	struct detail
  25. 	{
  26. 		virtual ~detail() {}
  27. 	};
  28.  
  29. 	template<class F>
  30. 	struct detail_impl : detail
  31. 	{
  32. 		F f_;
  33. 		detail_impl(F f) : f_(f) {
  34. 		}
  35. 	};
  36.  
  37. 	detail* pd;
  38. };
  39.  
  40. struct helloworld
  41. {
  42. 	void funcA() const {
  43. 		std::cout << "void helloworld::funcA()" << std::endl;
  44. 	}
  45.  
  46. 	int funcB(int, int) const {
  47. 		std::cout << "int helloworld::funcB(int, int)" << std::endl;
  48. 		return 0;
  49. 	}
  50. };
  51.  
  52. int main() {
  53. 	unsafe_func pf(&helloworld::funcA);
  54. 	unsafe_func pf2(&helloworld::funcB);
  55.  
  56. 	helloworld *p = 0;
  57.  
  58. 	pf.call<void>(p);
  59. 	pf2.call<int>(p, 0, 0);
  60.  
  61. 	return 0;
  62. }
Success #stdin #stdout 0s 3232KB
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void helloworld::funcA()
int helloworld::funcB(int, int)
https://ideone.com/4jGRDy
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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