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  1. #include <type_traits>
  2.  
  3. /* Row */
  4. struct T_cash_account_row {
  5.  
  6.     // Fields:
  7. 	enum T_field_enum { amount_of_money_e, gender_e, age_e, code_e, height_e,   /*<<<<<- add fields here (with index) */
  8. 		last_e	/*<<<<<- add included fields here (without index) */
  9. 	};
  10. static_assert(last_e > 0, "Number of indexed fields in enum of T_cash_account_row must be greater than 0!");
  11.  
  12.     	unsigned code:20;			// 0 - 1000000
  13. 	unsigned gender:1;			// 0 - 1
  14. 	unsigned age:7;			// 0 - 100	
  15. 	unsigned amount_of_money:20;	// 0 - 1000000
  16. 	unsigned height:9;			// 0 – 300
  17.  
  18.  
  19. 	// Get field value
  20. template<int field_enum> inline typename std::enable_if<field_enum == code_e, decltype(code)>::type	get_field_value() const { return code; }
  21.  
  22. template<int field_enum> inline typename std::enable_if<field_enum == gender_e, decltype(gender)>::type	get_field_value() const { return gender; }
  23.  
  24. template<int field_enum> inline typename std::enable_if<field_enum == age_e, decltype(age)>::type		get_field_value() const { return age; }
  25.  
  26. template<int field_enum> inline typename std::enable_if<field_enum == amount_of_money_e, decltype(amount_of_money)>::type get_field_value() const { return amount_of_money; }
  27.  
  28. template<int field_enum> inline typename std::enable_if<field_enum == height_e, decltype(height)>::type 	get_field_value() const { return height; }
  29.  
  30. template<int field_enum> inline typename std::enable_if<field_enum == last_e, bool>::type 				get_field_value() const { return true; }
  31.  
  32. static_assert(5 == last_e, "Add/delete new field-case and correct this assert!");
  33. };
  34. /* ----------------------------------------------------------------------- */
  35.  
  36. int main() {
  37.     T_cash_account_row *row = new T_cash_account_row;
  38.     auto code = row->get_field_value<T_cash_account_row::code_e>();
  39.  
  40.     return 0;
  41. }
  42.  
Success #stdin #stdout 0s 2980KB
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https://ideone.com/9yahUB
language:
C++14 (gcc 8.3)
created:
11 years ago
visibility:
public

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