boost shared_ptr factory function

I'm pretty new to the world of pointers an开发者_StackOverflow中文版d have run into a problem in my code. I have a factory class that spits out shared_ptr's. "Entity" is the base class for any type of shared_ptr that gets created from this method.

If I overwrite the pointer in the get_entity method, everything seems to work. If i overwrite the pointer in the get_pointer method it doesn't.

// 
// typedef boost::shared_ptr<Entity> EntityPtr;

Entity::EntityPtr EntityFactory::get_entity(int type) {

    // My default pointer if everything else falls through
    Entity::EntityPtr e = boost::make_shared<Entity>(type);
    std::cout << e->get_type() << std::endl; // Entity

    switch (type) {
    case 1:
        // This works
        e = boost::make_shared<TextEntity>(type);
        std::cout << e->get_type() << std::endl; // TextEntity
        break;
    case 2:
        // This doesn't work
        get_pointer(e, type);
        std::cout << e->get_type() << std::endl; // Entity
        break;
    }

    return e;

}

// This function can (possibly) overwrite the passed-in pointer
void EntityFactory::get_pointer(Entity::EntityPtr e, int type) {

    // ...

    e = boost::make_shared<TextEntity>(type);

    // ...
}

My reasons for passing "e" into the get_pointer method was because i don't always need to modify the pointer. In some cases get_pointer finishes without modifying the pointer at all.

I'm hoping someone can help shed some light on what i'm doing wrong here. Thanks!

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I'm pretty darn confusuled about wtf you're trying to do since you pass in integers to make_shared.

Your problem may be solved by accepting a reference to Entity::EntityPtr in get_pointer.