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  1. #include <iostream>
  2. #include <utility>
  3.  
  4.  
  5. template <typename T>
  6. struct base_type {};
  7.  
  8. template <>
  9. struct base_type<int> {
  10. 	static std::string get_type() {return "int";}	
  11. };
  12.  
  13. template <>
  14. struct base_type<float> {
  15. 	static std::string get_type() {return "float";}	
  16. };
  17.  
  18. // write more specializations for primitive and pointers and arrays, not important here
  19.  
  20.  
  21. struct ubiq_lref {
  22. 	std::string& out;
  23. 	std::string dummy;
  24. 	ubiq_lref(const int&_): out(dummy) {}
  25. 	ubiq_lref(std::string &x, const int& _): out(x) {}
  26.  
  27. 	template <typename T>
  28. 	operator T () {
  29. 		out += base_type<T>::get_type() + ", ";
  30. 		return T();
  31. 	}
  32. };
  33.  
  34.  
  35.  
  36. template <typename T, int ... ints> 
  37. struct reflect {
  38. 	static std::string get_members() {
  39. 		std::string s = "{";
  40. 		T{ubiq_lref(s, ints)...};
  41. 		s += "}";
  42. 		return s;
  43. 	}		
  44. };
  45.  
  46. template <typename T, int ... ints>
  47. auto get_str(int) ->typename  std::enable_if<std::is_same<decltype(T{ubiq_lref(ints)...}), T>::value, std::string>::type {
  48. 	return reflect<T, ints...>::get_members();
  49. }
  50.  
  51. template <typename T, int a, int...ints>
  52. auto get_str(long) -> std::string {
  53. 	return get_str<T, ints...>(0);
  54. }
  55.  
  56.  
  57. template <typename T, int...ints>
  58. std::string get_members(std::integer_sequence<int, ints...> _) {
  59. 	return get_str<T, ints...>(0);
  60. }
  61.  
  62.  
  63. struct foo {
  64. 	int x;
  65. 	float y;
  66. 	int z;
  67. };
  68.  
  69.  
  70. int main() {
  71. 	// your code goes here
  72. 	std::cout << get_members<foo>(std::make_integer_sequence<int, (int)sizeof(foo)>()) << std::endl;
  73. 	return 0;
  74. }
Success #stdin #stdout 0s 5288KB
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Standard input is empty
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{int, float, int, }
https://ideone.com/TemW5S
language:
C++14 (gcc 8.3)
created:
8 hours ago
visibility:
public

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