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  1. #include <iostream>
  2. #include <type_traits>
  3.  
  4. template< typename R, typename C, typename... Args>
  5. class delegate
  6. {
  7. public:
  8.     template<R(C::*F)(Args...), typename ... Ts>
  9.     struct adapter {
  10.         static R invoke_no_fwd(Args... args) {
  11.             C t(Ts::value...);
  12.             return (t.*F)(args...);
  13.         }
  14.     };
  15. };
  16.  
  17. class Class
  18. {
  19. public:
  20.     Class(int param) : m_val(param) {}
  21.     void print(int v) {
  22.         std::cout << "Class: " << v + m_val << std::endl;
  23.     }
  24. private:
  25.     int m_val;
  26. };
  27.  
  28. int main()
  29. {
  30.     typedef void(*function_t)(int);
  31.     function_t ptrFunc = (delegate<void, Class, int>::adapter<&Class::print, std::integral_constant<int, 42> >::invoke_no_fwd);
  32.     auto type = (delegate<void, Class, int>::adapter<&Class::print, std::integral_constant<int, 42>>::invoke_no_fwd);
  33.     ptrFunc(-42); // 0
  34.     type(0);      // 42
  35.     return 0;
  36. }
  37.  
Success #stdin #stdout 0s 3296KB
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stdin
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Standard input is empty
stdout
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Class: 0
Class: 42
https://ideone.com/YUg1TS
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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