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  1. #include <iostream>
  2. #include <functional>
  3.  
  4. using namespace std;
  5.  
  6. typedef std::function<void()> CallBack;
  7.  
  8. class TestChangeCallback
  9. {
  10. public:
  11. 	void Do(const int& a)
  12. 	{
  13. 		cout << "Before: "  << a << endl;
  14. 		m_Callback = std::bind(&TestChangeCallback::Do, this, 2);
  15. 		cout << "After: "  << a << endl;
  16. 	}
  17.  
  18. 	void Invoke()
  19. 	{
  20. 		cout << __FUNCTION__ << " start " << bool(m_Callback)<< endl;
  21. 		if (m_Callback)
  22. 		{
  23. 			m_Callback();
  24. 		}
  25. 		cout << __FUNCTION__ << " end " << bool(m_Callback)<< endl;
  26. 	}
  27.  
  28. 	CallBack m_Callback;
  29. };
  30.  
  31. int main() {
  32. 	TestChangeCallback test;
  33.  
  34. 	test.m_Callback = std::bind(&TestChangeCallback::Do, &test, 1);
  35. 	test.Invoke();
  36. 	cout << __FUNCTION__ << endl;
  37.  
  38. 	return 0;
  39. }
  40.  
Success #stdin #stdout 0s 3460KB
comments (?)
stdin 
Standard input is empty
stdout 
Invoke start 1
Before: 1
After: 1
Invoke end 1
main
https://ideone.com/QQ93Ld
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

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