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  1. #include <memory>
  2. #include <iostream>
  3. #include <string>
  4. #include <map>
  5. #include <array>
  6. using namespace std;
  7.  
  8. struct GameState{
  9. 	virtual string info() const = 0;
  10. };
  11. string GameState::info() const{
  12. 	return "GameState.info: ";
  13. }
  14. typedef shared_ptr<GameState> state_ptr;
  15.  
  16. struct MenuState : GameState{
  17. 	string info() const{ return GameState::info() + "Menu"; }
  18. };
  19.  
  20. struct PlayState : GameState{
  21. 	string info() const{ return GameState::info() + "Play"; }
  22. };
  23.  
  24. template<class T>
  25. state_ptr create(){ return shared_ptr<GameState>(new T()); }
  26. typedef state_ptr (*create_fptr)();
  27.  
  28. class Manager{
  29. private:
  30. 	state_ptr m_state;
  31. public:
  32. 	state_ptr state(){ return m_state; }
  33. 	state_ptr state(string name){
  34. 		static map<string, create_fptr> create_funcs = {
  35. 			{{"Menu"}, {create<MenuState>}},
  36. 			{{"Play"}, {create<PlayState>}}
  37. 		};
  38. 		return m_state = create_funcs[name]();
  39.  
  40. 	}
  41. 	state_ptr state(state_ptr state){
  42. 		return m_state = state;
  43. 	}
  44. };
  45.  
  46. int main(){
  47. 	Manager m;
  48.  
  49. 	array<string, 2> names = 
  50. 		{ "Menu", "Play" };
  51. 	array<state_ptr, 2> objects = 
  52. 		{ create<PlayState>(), create<MenuState>() };
  53.  
  54. 	for(auto name : names)
  55. 		cout << m.state(name)->info() << endl;
  56. 	for(auto object : objects)
  57. 		cout << m.state(object)->info() << endl;
  58.  
  59. 	return 0;
  60. }
Success #stdin #stdout 0s 3436KB
comments (?)
stdin
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Standard input is empty
stdout
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GameState.info: Menu
GameState.info: Play
GameState.info: Play
GameState.info: Menu
https://ideone.com/nEMYNG
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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