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  1. #include <iostream>
  2.  
  3.  
  4. template<typename ... AA>
  5. using hfX = void(*)(AA ... );
  6.  
  7. void hf1 (int a)
  8.  { std::cout<< "hf1"<<std::endl; }
  9.  
  10. void hf2 (int a, int i)
  11.  { std::cout<< "hf2 "<<i<<std::endl;}
  12.  
  13. template <typename Tf, Tf F>
  14. class Collection;
  15.  
  16. template <typename ... I, hfX<I...> F>
  17. class Collection<hfX<I...>, F>
  18.  {
  19.    public: 
  20.       int i_=56;
  21.  
  22.       template <std::size_t N = sizeof...(I)>
  23.       typename std::enable_if<N == 1U, void>::type test ()
  24.        {
  25.        	    F(0);
  26.        }
  27.  
  28.       template <std::size_t N = sizeof...(I)>
  29.       typename std::enable_if<N == 2U, void>::type test ()
  30.        {
  31.            F(0,i_+1);
  32.        }
  33.  };
  34.  
  35. int main ()
  36.  {
  37.    Collection<hfX<int>, hf1>       c1;
  38.    Collection<hfX<int,int>, hf2>  c2;
  39.  
  40.    c1.test(); // print "hf1"
  41.    c2.test(); // print "hf2 57"
  42.  }
Success #stdin #stdout 0s 3468KB
comments (?)
stdin 
Standard input is empty
stdout 
hf1
hf2 57
https://ideone.com/f20BEk
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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