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  1. // functional_test.cpp : Defines the entry point for the console application.
  2. //
  3.  
  4. #include <functional>
  5. #include <iostream>
  6.  
  7. template<class T1, class T2>
  8. inline void dump(const T1 &f1, const T2 &f2)
  9. {
  10. 	std::cout << std::boolalpha 
  11. 		<< "f1 : " << static_cast<bool>(f1) << std::endl
  12. 		<< "f2 : " << static_cast<bool>(f2) << std::endl;
  13. }
  14.  
  15.  
  16. int main(int , char* [])
  17. {
  18. 	std::function<void(void*)> f1;
  19. 	std::function<void(const void*)> f2;
  20.  
  21. 	std::cout << "Initial state: " << std::endl;
  22. 	dump(f1,f2);
  23.  
  24. 	// Expected compilation fail
  25. 	//std::cout << "assign value of f1 to f2: " << std::endl;
  26. 	//f2 = f1;
  27. 	//dump(f1,f2);
  28.  
  29. 	std::cout << "Assign value of f2 to f1: " << std::endl;
  30. 	f1 = f2; // Could fail, but didn't
  31. 	dump(f1,f2); // Should give false/false but outputs true/false
  32.  
  33. 	try {
  34. 		if(f1)
  35. 			f1(nullptr);
  36. 		else 
  37. 			std::cout << "Skip f1" << std::endl;
  38.  
  39. 		if(f2)
  40. 			f2(nullptr);
  41. 		else 
  42. 			std::cout << "Skip f2" << std::endl;
  43. 	} 
  44. 	catch(const std::exception &e)  {
  45. 		std::cerr << "Exception: " << e.what() << std::endl;
  46. 	}
  47.  
  48. 	return 0;
  49. }
  50.  
  51.  
Success #stdin #stdout 0s 3144KB
comments (?)
stdin 
Standard input is empty
stdout 
Initial state: 
f1 : false
f2 : false
Assign value of f2 to f1: 
f1 : false
f2 : false
Skip f1
Skip f2
https://ideone.com/Mwvw7s
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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