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  1. #include <cstddef>
  2.  
  3. template <class Src, class Dest> Dest* transfer_cv(Src *, Dest *p) { return p; }
  4. template <class Src, class Dest> const Dest* transfer_cv(const Src *, Dest *p) { return p; }
  5. template <class Src, class Dest> volatile Dest* transfer_cv(volatile Src *, Dest *p) { return p; }
  6. template <class Src, class Dest> const volatile Dest* transfer_cv(const volatile Src *, Dest *p) { return p; }
  7.  
  8. #define property_enable(type) typedef type property_container_type
  9. #define property_this transfer_cv( this, container_from_property(this) )
  10.  
  11. template <class Value>
  12. struct property_base
  13. {
  14.    typedef Value value_type;
  15.    value_type value;
  16. };
  17.  
  18. #define property struct : property_base
  19. #define property_set(...) void operator =(__VA_ARGS__)
  20. #define property_get(...) operator __VA_ARGS__()
  21. #define property_make(name) name; \
  22. static property_container_type* container_from_property(const volatile decltype(name)* p) \
  23. { \
  24.    return (property_container_type*) ((char*) p - offsetof(property_container_type, name)); \
  25. }
  26.  
  27. #include <iostream>
  28.  
  29. struct asdf {
  30.     property_enable(asdf);
  31.  
  32.     float myFloat;
  33.  
  34.     property<int>
  35.     {
  36.         property_set(int new_value) {
  37.             value = new_value * 2;
  38.             std::cout << "my float:" << property_this->myFloat << std::endl;
  39.         }
  40.         property_get(int) const {
  41.             return value - 1;
  42.         }
  43.     } property_make(member)
  44. };
  45.  
  46. int main()
  47. {
  48.     asdf x = { 2.0f };
  49.     x.member = 5;
  50.     std::cout << x.member;
  51. }
  52.  
Success #stdin #stdout 0s 2896KB
comments (?)
stdin 
Standard input is empty
stdout 
my float:2
9
https://ideone.com/ooErUU
language:
C++14 (gcc 8.3)
created:
11 years ago
visibility:
secret

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