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  1.  
  2. #include <map>
  3. #include <tuple>
  4. #include <string>
  5. #include <typeinfo>
  6.  
  7. #define REGISTER_ELEM( ELEM )    \
  8.     { Reflectable* p = this; }   \
  9.     register_element( #ELEM, typeid(ELEM).name(), &ELEM )
  10.  
  11.  
  12. struct Reflectable {
  13.  
  14. public:
  15. 	class Caster {
  16. 	public:
  17. 		Caster(void* ptr) : m_ptr(ptr) {}
  18. 		Caster() {}
  19.  
  20. 		template<typename T> operator T&() {
  21. 			return *reinterpret_cast<T*>(m_ptr);
  22. 		}
  23.  
  24. 	private:
  25. 		void* m_ptr;
  26.  
  27. 	};
  28.  
  29. 	Caster& get(const std::string key) {
  30. 		return std::get<1>(m_elements.at(key));
  31. 	}
  32.  
  33. 	std::string type(const std::string key) {
  34. 		return std::get<0>(m_elements.at(key));
  35. 	}
  36.  
  37. protected:
  38. 	void register_element(const std::string key, const std::string type_name, void* ptr) {
  39. 			m_elements[key] = std::make_tuple(type_name, Caster(ptr));
  40. 	}
  41.  
  42. private:
  43.  
  44. 	std::map<const std::string, std::tuple<std::string, Caster>> m_elements;
  45. };
  46.  
  47.  
  48. // main.cpp
  49.  
  50. #include <iostream>
  51.  
  52. struct Test : Reflectable {
  53. 	int a = 123;
  54. 	double b = 256;
  55.  
  56. 	Test() {
  57. 		REGISTER_ELEM(a);
  58. 		REGISTER_ELEM(b);
  59. 	}
  60. };
  61.  
  62. int main(void) {
  63. 	Test test;
  64.  
  65. 	int a = test.get("a");
  66. 	double b = test.get("b");
  67. 	std::cout << "a is " << a << std::endl;
  68. 	std::cout << "b is " << b << std::endl;
  69. }
  70.  
  71.  
Success #stdin #stdout 0s 15240KB
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stdin
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Standard input is empty
stdout
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a is 123
b is 256
https://ideone.com/zc6oHM
language:
C++14 (gcc 8.3)
created:
4 years ago
visibility:
public

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