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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. class Product
  5. {
  6. public:
  7.     int ID;
  8.     std::string Designation;
  9. };
  10.  
  11. struct Property
  12. {
  13.     std::string Name;
  14.     int Shift;
  15. };
  16.  
  17. class ProductSchema
  18. {
  19. private: 
  20.     ProductSchema();
  21. public: 
  22.     static ProductSchema& Default();
  23.     ProductSchema(const ProductSchema& other) = delete;
  24.     Property ID;
  25.     Property Designation;
  26.     Property Prix;
  27. };
  28. ProductSchema::ProductSchema()
  29. {  
  30.     ID.Name = "ID";
  31.     ID.Shift = offsetof(Product, ID);    
  32.  
  33.     Designation.Name = "Designation";
  34.     Designation.Shift = offsetof(Product, Designation);
  35. }
  36.  
  37. ProductSchema& ProductSchema::Default()
  38. {
  39.     static ProductSchema instance_;
  40.     return instance_;
  41. }
  42.  
  43. int main()
  44. {     
  45.     Product p;
  46.     p.ID = 12345;
  47.     cout << "Before: " << p.ID << endl;
  48.     int* pID = reinterpret_cast<int*>(reinterpret_cast<uintptr_t>(&p) + ProductSchema::Default().ID.Shift);
  49.     *pID = 67890;
  50.     cout << "After: " << p.ID << endl;
  51. }
Success #stdin #stdout 0.01s 5472KB
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stdin
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Standard input is empty
stdout
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Before: 12345
After: 67890
https://ideone.com/2xutrC
language:
C++ (gcc 8.3)
created:
3 years ago
visibility:
public

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