Add support for void AnySharedPointer

[codemercenary]

Allow users to retrieve std::shared_ptr<void> directly from an AnySharedPointer.

[ajohnston33]

This looks like a means of having an un-typed container for a pointer without losing type safety. I can understand wanting this to be able to write simpler template logic elsewhere. What confuses me here is throwing away your ability to guard type safe access by returning a shared_ptr<void>. Shouldn't callers need to provide the type of the underlying pointer so it can be checked before being allowed access to the shared pointer?

[codemercenary]

Quite correct. Actually, the main motivation to using AnySharedPointer is not necessarily that the code becomes any simpler, but that I can avoid using templated functions altogether and move to runtime versions of the same. These runtime versions are compiled once and don't increase build times downstream.

This particular routine is mainly intended to make unit tests a little easier to write in that sometimes I don't actually care about the underlying type, I just want whatever the pointed-to object is. There are implicit dangers of doing this--in particular:

std::shared_ptr<Derived> p;
AnySharedPointer x = std::static_pointer_cast<Base>(p);
ASSERT_EQ(p.get(), x.as_void());  // Might fail!

But we tolerate this because it's not really used by anyone except autowiring, and that's the only intended customer for now.

[codemercenary]

Also when I use this type I get burned almost every time and have to rely pretty heavily on unit tests to ensure correctness. It's definitely not the friendliest thing in the world.

[ajohnston33]

I am thinking something like this?

template<class T>
std::shared_ptr<T> as_shared(void) const {
  "Check that auto_id of T == m_ti"
  return static_pointer_cast<T>(m_ptr);
}

[codemercenary]

In fact, I have something like that now, it's called as