fork download
copy 
  1. #include <iostream>
  2.  
  3. namespace t1 {
  4. 	struct nullopt_t{};
  5. 	static const nullopt_t nullopt{};
  6.  
  7. 	template<typename T>
  8. 	struct optional
  9. 	{
  10. 		optional() { std::cout << "optional()" << std::endl; }
  11. 		optional(nullopt_t) { std::cout << "optional(nullopt)" << std::endl; }
  12. 	};	
  13. }
  14.  
  15. namespace my_very_own {
  16. 	using t1::nullopt;
  17. 	using t1::optional;
  18. } 
  19.  
  20. int main() {
  21. 	my_very_own::optional<int> opt1;
  22. 	my_very_own::optional<int> opt2 = my_very_own::nullopt;
  23. 	return 0;
  24. }
Success #stdin #stdout 0s 4488KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
optional()
optional(nullopt)
https://ideone.com/nkVrNH
language:
C++ 4.3.2 (gcc-4.3.2)
created:
3 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!