#include <stdio.h>
#include <iostream>
#include <memory>
#include <utility>
using namespace std;

#define T printf("%s [%d]\n", __PRETTY_FUNCTION__, val)

struct foo {
    foo(int x) : val(x) {
        T;
    }
    ~foo() {
        T;
    }
    void print() const {
        cout << "foo{" << val << "}\n";
    }

int val;
};

void print(shared_ptr<foo> x) {
    x->print();
}

int main() {
    shared_ptr<foo> x(new foo(5)); 
    print(x);
    if (x) x->print();
    //cout << *x << endl;
    {
        auto g = x;
        print(g);
    }
    print(x);
}