#include <iostream>
#include <memory>
 
using std::shared_ptr;
using std::weak_ptr;
using std::make_shared;
 
class A : public std::enable_shared_from_this<A>
{
public:
 
	class B{
	public:
		B(shared_ptr<A> ptr)  { //??
			ptrToA = ptr;
		} 
		~B(){}
	private:
		int bNumber{1};
		weak_ptr<A> ptrToA;
	};
 
 
	A(){
		ptrToB = make_shared<B>(shared_from_this());
	}
	~A(){}
	shared_ptr<B> getPtrToB() { return ptrToB; }
 
 
 
private:
	shared_ptr<B> ptrToB;
	int aNumber{0};
};
 
int main(){
	 std::shared_ptr<A> aInstance;
 
	return 0;
}

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