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  1. #include <iostream>
  2. #include <vector>
  3.  
  4. using namespace std;
  5.  
  6. enum typeData
  7. {
  8. 	ValueDouble,
  9. 	ValueFloat
  10. };
  11.  
  12. struct data
  13. {
  14.     typeData TypeData;
  15.     vector<double> getDoubleValues() const { return vector<double>(); }
  16.     vector<float> getFloatValues() const { return vector<float>(); }
  17. };
  18.  
  19. template <typename R, typename F, typename ...Args>
  20. R Dispatch2(const data& d1, const data& d2, F f, Args&&... args)
  21. {
  22.   if (d1.TypeData == ValueDouble && d2.TypeData == ValueDouble)
  23. 	return f(d1.getDoubleValues(), d2.getDoubleValues(), std::forward<Args>(args)...);
  24.  
  25.   if (d1.TypeData == ValueDouble && d2.TypeData == ValueFloat)
  26. 	return f(d1.getDoubleValues(), d2.getFloatValues(), std::forward<Args>(args)...);
  27.  
  28.   if (d1.TypeData == ValueFloat && d2.TypeData == ValueDouble)
  29. 	return f(d1.getFloatValues(), d2.getDoubleValues(), std::forward<Args>(args)...);
  30.  
  31.   if (d1.TypeData == ValueFloat && d2.TypeData == ValueFloat)
  32. 	return f(d1.getFloatValues(), d2.getFloatValues(), std::forward<Args>(args)...);
  33. }
  34.  
  35. //usage
  36. struct Context {}; //for additional args
  37.  
  38. template <typename T>
  39. struct D3
  40. {
  41.   template <typename V, typename ...Args>
  42.   T operator()(const std::vector<V>& v1, const std::vector<V>& v2, Args&&... args) const { return 1; }
  43.  
  44.   template <typename V1, typename V2, typename ...Args>
  45.   T operator()(const std::vector<V1>& v1, const std::vector<V2>& v2, Args&&... args) const { return 2; }
  46. };
  47.  
  48. int main()
  49. {
  50. 	data d1;
  51.     d1.TypeData = ValueDouble;
  52.  
  53.     data d2;
  54.     d2.TypeData = ValueFloat;
  55.  
  56.     Context ctx;
  57.  
  58.     int h1 = Dispatch2<int>(d1, d2, D3<int>(), ctx);
  59.     cout << "h1 = " << h1 << endl;
  60.  
  61.     d1.TypeData = ValueFloat;
  62.     int h2 = Dispatch2<int>(d1, d2, D3<int>(), ctx);
  63.     cout << "h2 = " << h2 << endl;
  64. 	return 0;
  65. }
Success #stdin #stdout 0s 3096KB
comments (?)
stdin 
Standard input is empty
stdout 
h1 = 2
h2 = 1
https://ideone.com/LO27uy
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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