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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. //прототипы шаблонов
  5. template <typename T> void counts();
  6. template <typename T> void report(T &);
  7.  
  8. //шаблонный класс
  9. template <typename TT>
  10. class HasFriendT
  11. {
  12. 	private:
  13. 	   TT item;
  14. 	   static int ct;
  15. 	public:
  16. 	   HasFriendT(const TT & i) : item(i) {ct++;}
  17. 	   ~HasFriendT( ) {ct--;}
  18. 	   friend void counts<TT>();
  19. 	   friend void report<>(HasFriendT<TT> &);
  20. };
  21. template <typename T>
  22. int HasFriendT<T>::ct = 0;
  23.  
  24. //определение дружественных функции для шаблона
  25. template <typename T>
  26. void counts()
  27. {
  28. 	cout << "template size: " << sizeof(HasFriendT<T>) << "; "; //размер шаблона
  29. 	cout << "template counts(): " << HasFriendT<T>::ct << endl;
  30. }
  31. template <typename T>
  32. void report(T & hf)
  33. {
  34. 	cout << hf.item << endl;
  35. }
  36.  
  37. int main()
  38. {
  39. 	counts<int>();
  40. 	HasFriendT<int> hfi1(10);
  41. 	HasFriendT<int> hfi2(20);
  42. 	HasFriendT<double> hfdb(10.5);
  43. 	report(hfi1);
  44. 	report(hfi2);
  45. 	report(hfdb);
  46. 	cout << "counts<int>() output:\n";
  47. 	counts<int>();
  48. 	cout << "counts<double> ( ) output: \n";
  49. 	counts<double>();
  50. 	return 0;
  51. }
  52.  
Success #stdin #stdout 0s 16056KB
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stdin
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Standard input is empty
stdout
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template size: 4; template counts(): 0
10
20
10.5
counts<int>() output:
template size: 4; template counts(): 2
counts<double> ( ) output: 
template size: 8; template counts(): 1
https://ideone.com/jToOkS
language:
C++14 (gcc 8.3)
created:
6 years ago
visibility:
public

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