boost:shared_ptr

The shared_ptr class template stores a pointer to a dynamically allocated object, typically with a C++ new-expression. The object pointed to is guaranteed to be deleted when the last shared_ptr pointing to it is destroyed or reset.

要考虑的是拷贝和赋值的情况，以及比较运算符，幸好这都在shared_ptr的设计之下。

但，shared_ptr不能正确的处理数组指针，如果需要，可以考虑shared_arry

而且，需要注意循环计数的情况，以及在构造函数中的使用。

Q. Why doesn't shared_ptr (or any of the other Boost smart pointers) supply an automatic conversion to T*?

A. Automatic conversion is believed to be too error prone.

Y

ou 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:

class Y: public 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.