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  1. #include <iostream>
  2. #include <cstdlib>
  3. using namespace std;
  4.  
  5.     typedef int HANDLE;
  6.  
  7.     void DeleteHandle(HANDLE h)
  8.     {
  9.         cout << "deleting handle " << h << endl;
  10.     }
  11.  
  12.     template <class H>
  13.     class UniqueHandle {
  14.         H h;
  15.  
  16.     public:
  17.         UniqueHandle(H _h = 0)
  18.             :h(_h) {}
  19.  
  20.         UniqueHandle(const UniqueHandle &other)
  21.             :h(const_cast<UniqueHandle&>(other).YieldOwnership()) {}
  22.  
  23.         ~UniqueHandle() { ::DeleteHandle(h); }
  24.  
  25.         UniqueHandle &operator =(const UniqueHandle &other)
  26.         {
  27.             this->~UniqueHandle(); // release the old handle
  28.             h = const_cast<UniqueHandle&>(other).YieldOwnership();
  29.             return *this;
  30.         }
  31.  
  32.         UniqueHandle &operator =(H _h)
  33.         {
  34.             this->~UniqueHandle(); // release the old handle
  35.             h = _h;
  36.             return *this;
  37.         }
  38.  
  39.         H YieldOwnership() { H result = h; h = 0; return result; }
  40.  
  41.         operator H() const { return h; }
  42.     };
  43.  
  44. int main()
  45. {
  46. 	UniqueHandle<HANDLE> h(123);
  47. 	UniqueHandle<HANDLE> h2 = 456;
  48. 	HANDLE unmanaged = 789;
  49. 	HANDLE mixed_case = (rand() & 1)? (HANDLE)h : unmanaged;
  50. 	DeleteHandle(unmanaged);
  51. 	return 0;
  52. }
Success #stdin #stdout 0s 3340KB
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stdin
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Standard input is empty
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deleting handle 789
deleting handle 456
deleting handle 123
https://ideone.com/kzW7nN
language:
C++ (gcc 8.3)
created:
10 years ago
visibility:
public

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