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  1. #include <iostream>
  2. #include <functional>
  3. #include <vector>
  4. #include <memory>
  5. #include <random>
  6.  
  7. struct Base
  8. {
  9.     virtual void print() const = 0;
  10.     virtual ~Base() {}
  11. };
  12.  
  13.  
  14. struct D1 : public Base { void print() const { std::cout << "D1\n"; } };
  15. struct D2 : public Base { void print() const { std::cout << "D2\n"; } };
  16. struct D3 : public Base { void print() const { std::cout << "D3\n"; } };
  17. struct D4 : public Base { void print() const { std::cout << "D4\n"; } };
  18. struct D5 : public Base { void print() const { std::cout << "D5\n"; } };
  19.  
  20.  
  21. template <typename T>
  22. T* new_class()
  23. {
  24.     return new T;
  25. }
  26.  
  27. typedef std::function<Base*()> creationFunction;
  28.  
  29. enum class_type { eD1, eD2, eD3, eD4, eD5 };
  30.  
  31. creationFunction create [] =
  32. {
  33.     new_class<D1>,
  34.     new_class<D2>,
  35.     new_class<D3>,
  36.     new_class<D4>,
  37.     new_class<D5>
  38. };
  39.  
  40. Base* getClass(class_type type)
  41. {
  42.     return create[type]();
  43. }
  44.  
  45. int main()
  46. {
  47.     std::mt19937 engine( (std::random_device())() );
  48.     std::uniform_int_distribution<unsigned> ct(eD1, eD5);
  49.  
  50.     auto rand_class = [&]() { return static_cast<class_type>(ct(engine)); };
  51.  
  52.     std::vector<std::unique_ptr<Base>> container;
  53.     for (unsigned i = 0; i < 20; ++i)
  54.         container.emplace_back(getClass(rand_class()));
  55.  
  56.     for (auto & element : container)
  57.         element->print();
  58. }
Success #stdin #stdout 0s 3432KB
comments (?)
stdin 
Standard input is empty
stdout 
D5
D5
D5
D3
D2
D1
D5
D1
D3
D2
D5
D3
D1
D3
D5
D2
D5
D1
D3
D5
https://ideone.com/aLOQN0
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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