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  1. #include <iostream>
  2. #include <utility>
  3. #include <memory>
  4.  
  5. template <typename V, typename T> 
  6. 	char  test(V&& v, T&& t, decltype( (t.*v)((int)0), 0 ) = 0)
  7. 	//char  test(V&& v, T&& t, decltype( (t.*v)((int)0) )* = 0)
  8. 	{ return 0; }
  9.  
  10. template <typename V, typename T> 
  11. 	short test(V&& v, T&& t, decltype( (*t.*v)((int)0), 0 ) = 0)
  12. 	//short test(V&& v, T&& t, decltype( (*t.*v)((int)0) )* = 0)
  13. 	{ return 0; }
  14.  
  15. long  test(...)  { return 0; }
  16.  
  17. namespace { int static_a; }
  18.  
  19. struct ichikawa	{
  20. 	int fun1(int a) const { return 2*a; }
  21. 	int& fun2(int a) const { return static_a; }
  22. 	int&& fun3(int a) const { return (int&&)static_a; }
  23. 	};
  24.  
  25. int main() {
  26. 	ichikawa ic;
  27. 	std::unique_ptr<ichikawa> sp(new ichikawa);
  28. 	//int (ichikawa::*pF)(int)const = &ichikawa::fun1;
  29. 	//int& (ichikawa::*pF)(int)const = &ichikawa::fun2;
  30. 	int&& (ichikawa::*pF)(int)const = &ichikawa::fun3;
  31.  
  32. 	auto result1 = test(pF, ic);
  33. 	auto result2 = test(pF, &ic);
  34. 	auto result3 = test(pF, sp);
  35.  
  36. 	std::cout << sizeof(result1) << std::endl;
  37. 	std::cout << sizeof(result2) << std::endl;
  38. 	std::cout << sizeof(result3) << std::endl;
  39.  
  40. 	std::conditional< 0 < 2, int, char>::type nakamura;
  41. 	std::conditional< (0 > 3), int, char>::type kataoka;
  42.  
  43. 	return 0;
  44. }
Success #stdin #stdout 0s 3472KB
comments (?)
stdin 
Standard input is empty
stdout 
1
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https://ideone.com/Ykulus
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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