On Thursday, July 9, 2009, Frank Mori Hess <frank.hess@nist.gov> wrote:
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I wonder if it might be better/possible to have a shared_ptr<T> that didn't assume its corresponding "raw" pointer type was T* but rather T. For example, what is now a shared_ptr<int> would be specified as a shared_ptr<int*>. The motivation would be to allow support for other classes as the "raw" pointer type. For example, I might want to have a shared_ptr<monitor<T*> > where the monitor<T*> has an operator->() which does automatic locking/unlocking of a mutex before/after forwarding the operator->() to the plain T pointer.
I don't think lock/unlock on each -> call is typically a good idea. x = p->x; y = p->y; That's 2 lock unlock sequences instead of one. Inefficient and what if y changes after you read x? It hides the locking too much, potentially leading to abuse and mistakes. I think alexandrescu has an article about this somewhere. (he also has articles about how to implement locking -> operators but I think he later recanted on the whole idea) Tony