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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. template <class T>
  5. class shared_ptrx
  6. {
  7. private:
  8. 	long *refcount;
  9. 	T *link;
  10. 	void decrement() {
  11. 		if ((--(*refcount)) == 0) {
  12. 			delete refcount; 
  13. 			if (link != NULL) {
  14. 				delete link;
  15. 			}
  16. 		}
  17. 		refcount = NULL;
  18. 		link = NULL;
  19. 	}
  20. 	void init(T *t, long c) {
  21. 		refcount = new long(c);
  22. 		link = t;
  23. 	}
  24. 	void copy(shared_ptrx& p) {
  25. 		refcount = p.refcount;
  26. 		link = p.link;
  27. 		(*refcount)++;
  28. 	}
  29. public:
  30. 	shared_ptrx() { init(NULL, 0); } 
  31. 	explicit shared_ptrx(T *t) { init(t, 1); }
  32. 	explicit shared_ptrx(shared_ptrx& p) { copy(p);	}
  33. 	~shared_ptrx() { decrement(); }
  34. 	T& operator * () const { return *link; }
  35. 	T* operator -> () const { return link; }
  36. 	explicit operator bool () const {
  37. 		if (refcount == NULL) return false;
  38. 		return (*refcount > 0);
  39. 	}
  40. 	shared_ptrx& operator = (shared_ptrx& p) {
  41. 		decrement();
  42. 		copy(p);
  43. 		return *this;
  44. 	}
  45. 	void reset(T *t) {
  46. 		decrement();
  47. 		init(t, 1);
  48. 	}
  49. 	void swap(shared_ptrx& p) {
  50. 		int *rc = p.refcount;
  51. 		T *temp = p.link;
  52. 		p.refcount = refcount;
  53. 		p.link = link;
  54. 		refcount = rc;
  55. 		link = temp;
  56. 	}
  57. };
  58.  
  59. template <class T>
  60. class BaseList
  61. {
  62. private:
  63. 	BaseList *link;
  64. 	shared_ptrx<T> data;
  65. public:
  66. 	BaseList() : link(NULL) { }
  67. 	BaseList(T *t) : link(NULL) { data.reset(t); }
  68. 	void attach(const BaseList& p) {
  69. 		link = &p;
  70. 	}
  71. };
  72.  
  73. class Value
  74. {
  75. 	int c;
  76. public:
  77. 	Value(int v) { c = v; }
  78. 	~Value() { cout << "del!" <<  c << endl; }
  79. 	void p() { cout << c << endl; }
  80. 	operator int () { return c; }
  81. };
  82.  
  83. int main() {
  84.  
  85. 	shared_ptrx<Value> f(new Value(5));
  86. 	{
  87. 		shared_ptrx<Value> p(f);
  88. 		cout << *p << endl;
  89. 	}
  90. 	f->p();
  91.  
  92. 	{
  93. 		shared_ptrx<Value> m(new Value(8));
  94. 		shared_ptrx<Value> k(m);
  95. 		k = f;
  96. 		k->p();
  97. 		m->p();
  98. 	}
  99.  
  100. 	cout << "finish" << endl;
  101. 	return 0;
  102. }
Success #stdin #stdout 0s 3428KB
comments (?)
stdin 
Standard input is empty
stdout 
5
5
5
8
del!8
finish
del!5
https://ideone.com/Kcu2LL
language:
C++ (gcc 8.3)
created:
11 years ago
visibility:
public

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