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  1. #include <iostream>
  2. #include <map>
  3. #include <memory>
  4.  
  5. struct Base {
  6.     virtual ~Base() {} // do not forget this if you need polymorphism
  7. };
  8.  
  9. template <typename T>
  10. std::unique_ptr<Base> makeBase() { return std::unique_ptr<Base>(new T{}); }
  11.  
  12. using BaseMaker = std::unique_ptr<Base>(*)();
  13.  
  14. struct DerivedOne: Base {}; struct DerivedTwo: Base {};
  15.  
  16. using BaseMakerMap = std::map<std::string, BaseMaker>;
  17.  
  18. BaseMakerMap const map = { { "DerivedOne", makeBase<DerivedOne> },
  19.                            { "DerivedTwo", makeBase<DerivedTwo> } };
  20.  
  21. std::unique_ptr<Base> makeFromName(std::string const& n) {
  22.     BaseMakerMap::const_iterator it = map.find(n);
  23.  
  24.     if (it == map.end()) { return std::unique_ptr<Base>(); } // not found
  25.  
  26.     BaseMaker maker = it->second;
  27.  
  28.     return maker();
  29. }
  30.  
  31. int main() {
  32. 	makeFromName("DerivedOne");
  33. 	return 0;
  34. }
Success #stdin #stdout 0s 3468KB
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https://ideone.com/sjOCO0
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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