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  1. #include <tuple>
  2. #include <random>
  3. #include <functional>
  4.  
  5. typedef std::tuple<unsigned char,unsigned char,unsigned char> rgb_tuple;
  6.  
  7. class color_table{
  8. public:
  9.     void generate(std::function<rgb_tuple(const unsigned char&)> predicate);
  10.     unsigned char red_table[255];
  11.     unsigned char green_table[255];
  12.     unsigned char blue_table[255];
  13. };
  14.  
  15. template <class RANDOM>
  16. static rgb_tuple random_color(RANDOM engine){
  17.     std::uniform_int_distribution<int> dist1 (0,255);
  18.     unsigned char red   = (unsigned char) dist1(engine);
  19.     unsigned char green = (unsigned char) dist1(engine);
  20.     unsigned char blue  = (unsigned char) dist1(engine);
  21.     return std::make_tuple(red, green, blue);
  22. }
  23.  
  24. template <class RANDOM>
  25. static color_table create_random_color_map(RANDOM engine){
  26.     color_table lut;
  27.     lut.generate([&](const unsigned char& i)->rgb_tuple {
  28.         return random_color(engine);
  29.     } );
  30.     return lut;
  31. }
  32.  
  33. void color_table::generate(std::function<rgb_tuple(const unsigned char&)> predicate){
  34.     for(int i = 0; i < 256; ++i){
  35.         std::tie(red_table[i], green_table[i], blue_table[i]) = predicate(i);
  36.     }
  37. }
  38.  
  39. int main()
  40. {
  41.     std::mt19937 engine;
  42.     create_random_color_map(engine);
  43. }
  44.  
Success #stdin #stdout 0s 2980KB
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https://ideone.com/TrPobZ
language:
C++14 (gcc 8.3)
created:
12 years ago
visibility:
public

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