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  1. #include <iostream>
  2. #include <stdexcept>
  3.  
  4. #include <boost/any.hpp>
  5.  
  6. class Committer
  7. {
  8. public:	
  9.  
  10. 	template <typename T>
  11. 	void mark_var_change(T *var)
  12. 	{
  13. 	    mPointer = var;
  14. 	}
  15.  
  16. 	template <typename T>
  17. 	void commit_change(T new_value)
  18. 	{
  19. 		T* pointer = boost::any_cast<T*>(mPointer); // throw with bad type
  20. 		if (pointer == nullptr) {
  21. 			throw std::runtime_error("nullptr was stocked");
  22. 		}
  23. 	    *pointer = new_value;
  24. 	}
  25.  
  26. private:
  27.     boost::any mPointer;
  28. };
  29.  
  30.  
  31. int main() {
  32. 	Committer c;
  33. 	int i;
  34. 	float f;
  35.  
  36. 	c.mark_var_change(&i);
  37. 	c.commit_change(42);
  38.  
  39. 	c.mark_var_change(&f);
  40. 	c.commit_change(4.2f);
  41.  
  42. 	std::cout << i << " " << f << std::endl;
  43. }
  44.  
Success #stdin #stdout 0s 3280KB
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Standard input is empty
stdout
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42 4.2
https://ideone.com/fxO35C
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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