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  1. #include <iostream>
  2. #include <memory>
  3.  
  4. class Foo
  5. {
  6. 	std::string name;
  7. 	Foo(const std::string& _name) : name(_name) {}
  8. public:
  9. 	void doIt() const { std::cout << "Foo::doIt() <" << name << '>' << std::endl;}
  10. 	virtual ~Foo() { std::cout << "~Foo() <" << name << '>' << std::endl;}
  11.  
  12. 	static std::unique_ptr<Foo> create_unique(const std::string & _name) {
  13. 		return std::unique_ptr<Foo>(new Foo(_name));
  14. 	}
  15. 	static std::shared_ptr<Foo> create_shared(const std::string & _name) { 
  16. 		return std::shared_ptr<Foo>(new Foo(_name));
  17. 	}
  18.  
  19. 	static std::shared_ptr<Foo> to_shared(std::unique_ptr<Foo> &&ptr ) { 
  20. 		 return std::shared_ptr<Foo>(std::move(ptr)); 
  21. 	}
  22. 	static std::shared_ptr<Foo> get_shared(const std::shared_ptr<Foo> &ptr) {
  23. 		 return std::shared_ptr<Foo>(std::move(ptr));
  24. 	}
  25. };
  26.  
  27. int main() {
  28. 	// ok behavior
  29. 	auto pb1 = Foo::create_unique("pb1");
  30. 	pb1->doIt();
  31. 	std::shared_ptr<Foo> pb2 = Foo::get_shared(std::move(pb1));
  32. 	//note the change below
  33. 	std::shared_ptr<Foo> pb3 = Foo::get_shared(pb2);
  34. 	pb3->doIt();
  35.  
  36. 	// also OK behavior
  37. 	auto pb4 = Foo::create_unique("pb4");
  38. 	pb4->doIt();
  39. 	std::shared_ptr<Foo> pb5 = Foo::to_shared(std::move(pb4)); // no exception now
  40. 	pb5->doIt();
  41.  
  42. 	std::shared_ptr<Foo> pb6 = Foo::create_shared("pb6");
  43. 	pb6->doIt();
  44. 	std::shared_ptr<Foo> pb7 = std::shared_ptr<Foo>(pb6);
  45. 	pb7->doIt();
  46. 	return 0;
  47. }
Success #stdin #stdout 0s 3464KB
comments (?)
stdin
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Standard input is empty
stdout
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Foo::doIt() <pb1>
Foo::doIt() <pb1>
Foo::doIt() <pb4>
Foo::doIt() <pb4>
Foo::doIt() <pb6>
Foo::doIt() <pb6>
~Foo() <pb6>
~Foo() <pb4>
~Foo() <pb1>
https://ideone.com/UqIi3k
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

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