Consider using std::shared_ptr instead of raw pointers in usSharedData.h

[jeffdiclemente]

std::shared_ptr can now be used for all instances where SharedData, SharedDataPointer, and ExplicitlySharedDataPointer were used.
Doing this will add robustness to the code base and make maintenance easier.

[saschazelzer]

I am not sure I understand this. The mentioned classes implemented the COW pattern (copy on write). SharedDataPointer does so implicitly (when calling non-const methods on an object with ref count > 1) and ExplicitlySharedDataPointer only detaches a shared instance on explicit request. How can std::shared_ptr be used instead while keeping this functionality?

[jeffdiclemente]

It helps if I read the code a little more closely...

You're right, the SharedDataPointer and ExplicitlySharedDataPointer can't be completely replaced with std::shared_ptr since they are used for copy-on-write.

After looking again, I can only say that perhaps we should consider using std::shared_ptr instead of a raw pointer within SharedDataPointer and ExplicitlySharedDataPointer to store the shared data object.

Additionally, I think there is a bug in usSharedData.h on line 75:
inline const T* Data() const { return d; }.
Shouldn't this be inline T* Data() const { return d; }?

[jeffdiclemente]

no longer relevant.