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  1. /*!
  2.  * @file GenericImage_typeDispatch.cpp
  3.  * @brief
  4.  * @author vectra
  5.  * @date 16/05/19
  6.  */
  7.  
  8. #include <iostream>
  9. #include <vector>
  10. #include <exception>
  11. #include <array>
  12.  
  13.  
  14. using namespace std;
  15.  
  16.  
  17. // =============================================================================
  18. // type helpers
  19. // =============================================================================
  20.  
  21.  
  22. template < typename T >
  23. void showType(T var)
  24. { throw; }
  25.  
  26. template <>
  27. void showType(double var)
  28. { cout << "double"; }
  29.  
  30. template <>
  31. void showType(int var)
  32. { cout << "int"; }
  33.  
  34. template <>
  35. void showType(float var)
  36. { cout << "float"; }
  37.  
  38.  
  39.  
  40. // =============================================================================
  41. // dummy typed image class (implemented likewise by many real image libs)
  42. // =============================================================================
  43.  
  44.  
  45. class Image
  46. {
  47.  public:
  48.  
  49.   enum class Type
  50.   {
  51.     Float64,
  52.     Float32,
  53.     Int32,
  54.   } type_;
  55.  
  56.   std::size_t voxel_count_;
  57.   void        *data_ptr_ = nullptr;
  58.  
  59.   Image()
  60.   {}
  61.  
  62.   void
  63.   allocate(Image::Type t, size_t voxel_count)
  64.   {
  65.     type_        = t;
  66.     voxel_count_ = voxel_count;
  67.  
  68.     switch (t)
  69.       {
  70.         case Image::Type::Float64:
  71.           data_ptr_ = static_cast<void *>(new double[voxel_count]);
  72.         break;
  73.         case Image::Type::Int32:
  74.           data_ptr_ = static_cast<void *>(new int[voxel_count]);
  75.         break;
  76.         default:
  77.           throw;
  78.       }
  79.   }
  80.  
  81.   void
  82.   set_data(Image::Type t, void *data)
  83.   {
  84.     if ( data_ptr_ != nullptr ) throw;
  85.     type_     = t;
  86.     data_ptr_ = data;
  87.   }
  88. };
  89.  
  90.  
  91. // =============================================================================
  92. // Dispatcher mother, where all ropes are hidden from the user
  93. // =============================================================================
  94.  
  95.  
  96. template < class Derived >
  97. class ExecutorMother
  98. {
  99.  public:
  100.   Image *img_ = nullptr;
  101.  
  102.   ExecutorMother(Image *img) : img_(img)
  103.   {}
  104.  
  105.   // would like this one here!
  106.   /*
  107.   template < class ... ArgsType >
  108.   void
  109.   operator()(ArgsType ... arguments)
  110.   {
  111.     if ( ExecutorMother::img_ -> data_ptr_ == nullptr ) throw;
  112.     Derived &derived = static_cast<Derived &>(*this);
  113.     
  114.     switch (ExecutorMother::img_ -> type_)
  115.       {
  116.         case Image::Type::Float64:
  117.           {
  118.             derived . filter_function(arguments ...);
  119.             break;
  120.           }
  121.         case Image::Type::Float32:
  122.           {
  123.             derived . filter_function(arguments ...);
  124.             break;
  125.           }
  126.         case Image::Type::Int32:
  127.           {
  128.             derived . filter_function(arguments ...);
  129.             break;
  130.           }
  131.         default:
  132.           throw;// std::bad_exception;
  133.       }
  134.   }
  135.   */
  136.  
  137. };
  138.  
  139.  
  140. // =============================================================================
  141. // Dispatcher mother, where all ropes are hidden from the user
  142. // =============================================================================
  143.  
  144.  
  145. class CustomDispatcher : public ExecutorMother<CustomDispatcher>
  146. {
  147.  public:
  148.  
  149.   CustomDispatcher(Image *img) : ExecutorMother(img)
  150.   {}
  151.  
  152.  
  153.   template < typename ImgDataType >
  154.   void
  155.   filter_function(ImgDataType trigger_val, int iters, float dummy)
  156.   {
  157.     ImgDataType *data = static_cast<ImgDataType *>(ExecutorMother::img_ -> data_ptr_);
  158.  
  159.     cout << endl << "Types for filter: ";
  160.     showType(data[0]);
  161.     cout << " / arg1: ";
  162.     showType(trigger_val);
  163.     cout << " / arg2: ";
  164.     showType(iters);
  165.     cout << " / arg3: ";
  166.     showType(dummy);
  167.  
  168.  
  169.     for (size_t i = 0; i < ExecutorMother::img_ -> voxel_count_; i ++)
  170.       {
  171.         if ( data[i] == trigger_val )
  172.           data[i] = data[i] + iters;
  173.       }
  174.   }
  175.  
  176.  
  177.   /*
  178.    * @brief would like this one hidden in motherclass
  179.    */
  180.   template < class ... ArgsType >
  181.   void
  182.   operator()(ArgsType ... arguments)
  183.   {
  184.     if ( ExecutorMother::img_ -> data_ptr_ == nullptr ) throw;
  185.  
  186.     switch (ExecutorMother::img_ -> type_)
  187.       {
  188.         case Image::Type::Float64:
  189.           {
  190.             filter_function<double>(arguments ...);
  191.             break;
  192.           }
  193.         case Image::Type::Float32:
  194.           {
  195.             filter_function<float>(arguments ...);
  196.             break;
  197.           }
  198.         case Image::Type::Int32:
  199.           {
  200.             \
  201.           filter_function<int>(arguments ...);
  202.             break;
  203.           }
  204.         default:
  205.           throw;// std::bad_exception;
  206.       }
  207.   }
  208.  
  209.  
  210. };
  211.  
  212.  
  213. int main()
  214. {
  215.   std::array<int, 8> data = {1, 2, 3, - 32768, 5, 6, 7, 8};
  216.  
  217.   Image imgd;
  218.   imgd . allocate(Image::Type::Float64, 2 * 4);
  219.   Image imgi;
  220.   imgi . allocate(Image::Type::Int32, 2 * 4);
  221.  
  222.  
  223.   CustomDispatcher execd(&imgd);
  224.   execd(- 32768, 32000, 3.14);
  225.   CustomDispatcher execi(&imgi);
  226.   execi(- 32768, 32000, 3.14);
  227.  
  228.  
  229.   return 0;
  230. }
Success #stdin #stdout 0s 15240KB
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Standard input is empty
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Types for filter: double / arg1: double / arg2: int / arg3: float
Types for filter: int / arg1: int / arg2: int / arg3: float
https://ideone.com/cBE6Df
language:
C++ (gcc 8.3)
created:
4 years ago
visibility:
public

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