fork download 
  1. #include <iostream>
  2. #include <string>
  3. #include <map>
  4.  
  5. class ValueHolder
  6. {
  7. 	public:
  8. 		int **put(const std::string &key)
  9. 		{
  10. 			//throw if key exists
  11. 			auto val = values.emplace(key, nullptr);
  12. 			return &val.first->second;
  13. 		}
  14. 		void init()
  15. 		{
  16. 			for (auto &it: values)
  17. 				it.second = new int(10);
  18. 		}
  19. 		void print()
  20. 		{
  21. 			for (auto &it: values)
  22. 				std::cout<<*it.second<<std::endl;
  23. 		}
  24. 	private:
  25. 		std::map<std::string, int *> values;
  26. };
  27.  
  28.  
  29. int main() 
  30. {
  31. 	ValueHolder holder;
  32. 	int **ptr = holder.put("Test");
  33. 	std::cout<<"ptr == nullptr: "<< (*ptr == nullptr)<<std::endl;
  34.  
  35. 	holder.init();
  36. 	std::cout<<"ptr == nullptr: "<< (*ptr == nullptr)<<std::endl;
  37. 	std::cout<<**ptr<<std::endl;
  38.  
  39. 	**ptr = 100;
  40. 	holder.print();
  41.  
  42. 	return 0;
  43. }
Success #stdin #stdout 0s 3416KB
comments (?)
stdin 
Standard input is empty
stdout 
ptr == nullptr: 1
ptr == nullptr: 0
10
100
https://ideone.com/B25kqS
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!