Question

will using a shared_ptr on class instance members clean up the new’ed objects correctly when the owning “parent” drops out of scope? Like in the example below?

Code example below – so when the Family instance goes out of scope will it clean up/delete the people objects linked to in the map?

If so how can i confirm this? Are there tools i can use to show before and after – after showing no person object – and if i put the normal pointers back i should still see the person objects – thanks

class Family
{
private:
    //std::map<int ,Person*> _people;
    std::map<int ,std::tr1::shared_ptr<Person>> _people;

public:
    void AddPerson(int age)
    {
        //_people[age] = new Person(age);
        _people[age] = std::tr1::shared_ptr<Person>( new Person(age));
    }
};

    class Person
    {
    private:
        int _age;
    public: 
        Person(int age)
        {
            _age= age;
        }
        int GetName(){return _age;}
    };

Answer 1

Go through it: Family goes out of scope, _people is destroyed, the map destructor removes all it’s elements, which means that for each element, the destructor is called. All shared_ptrS in the map decrement their reference count. If the reference count is now 0, the objects are destroyed. Although I don’t see why you would store a pointer (smart or not) in your example, I guess you have your reasons.