#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <queue>
#include <vector>
#include <list>
#include <functional>
#include <memory>
 
struct Son {
    // some data that we want to point to
    ~Son(){printf("Bye Son\n");}
};
 
struct Father {
    Son son;
    Father(){}
    ~Father(){printf("Bye Father\n");}
};
 
int main(){
    std::shared_ptr<Father> father = std::make_shared<Father>();
    std::shared_ptr<Son> son(father, &father->son);
    printf("%d\n", father.use_count());
    printf("%d\n", son.use_count());
    father.reset();
    printf("%d\n", father.use_count());
    printf("%d\n", son.use_count());
    printf("%d\n", father.owner_before(son));
    printf("%d\n", son.owner_before(father));
}
 

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