Getting a boost::shared_ptr for this

Solution 1:

You can derive from enable_shared_from_this and then you can use "shared_from_this()" instead of "this" to spawn a shared pointer to your own self object.

Example in the link:

#include <boost/enable_shared_from_this.hpp>

class Y: public boost::enable_shared_from_this<Y>
{
public:

    shared_ptr<Y> f()
    {
        return shared_from_this();
    }
}

int main()
{
    shared_ptr<Y> p(new Y);
    shared_ptr<Y> q = p->f();
    assert(p == q);
    assert(!(p < q || q < p)); // p and q must share ownership
}

It's a good idea when spawning threads from a member function to boost::bind to a shared_from_this() instead of this. It will ensure that the object is not released.

Solution 2:

Just use a raw pointer for your function parameter instead of the shared_ptr. The purpose of a smart pointer is to control the lifetime of the object, but the object lifetime is already guaranteed by C++ scoping rules: it will exist for at least as long as the end of your function. That is, the calling code can't possibly delete the object before your function returns; thus the safety of a "dumb" pointer is guaranteed, as long as you don't try to delete the object inside your function.

The only time you need to pass a shared_ptr into a function is when you want to pass ownership of the object to the function, or want the function to make a copy of the pointer.