Add a tutorial on allocator support

[RyanJK5]

First draft of a tutorial. Walks through adding basic default-initialized allocator support, then stateful allocators and copy semantics, and finally allocator-aware move and swap semantics.

Closes #139.

[RyanJK5]

@jbcoe I put together this draft of the tutorial, but it definitely needs some work. Do you have any suggestions to avoid duplicating Owner between each of the steps of the tutorial? I considered out-of-line definitions, but I'm concerned it may be a bit overwhelming to show the entire allocator-aware class definition right after step 1. That being said, it may be less confusing than rewriting the class like I'm doing now.

[jbcoe]

This looks great on a first pass.

Maybe we could introduce the allocator-extended constructors as a step on their own?

[RyanJK5]

@jbcoe Do we care about the exception guarantee for this demonstration? Right now it's using the basic guarantee because it made showcasing a little simpler, but if protocol is going to use a strong guarantee, I could change the tutorial to match.

[jbcoe]

@jbcoe Do we care about the exception guarantee for this demonstration? Right now it's using the basic guarantee because it made showcasing a little simpler, but if protocol is going to use a strong guarantee, I could change the tutorial to match.

It might be useful to add as another stage. We would like a strong exception guarantee if possible.

[jbcoe]

@jbcoe I put together this draft of the tutorial, but it definitely needs some work. Do you have any suggestions to avoid duplicating Owner between each of the steps of the tutorial? I considered out-of-line definitions, but I'm concerned it may be a bit overwhelming to show the entire allocator-aware class definition right after step 1. That being said, it may be less confusing than rewriting the class like I'm doing now.

I would not worry about duplicating Owner. We do similar things in other tutorials, although for smaller classes.

[jbcoe]

@RyanJK5 I merged main, please let me know if you'd rather that I did not do this.

[jbcoe]

Thanks for this.

[RyanJK5]

Sorry to re-request, but the exception section turned out to be fairly sizable.

[jbcoe]

Sorry to re-request, but the exception section turned out to be fairly sizable.

Happy to re-review.

[jbcoe]

Formatting here is not ideal. Not blocking but I wonder if our .clang-format settings can be improved?

[RyanJK5]

Good catch, I would expect the requires clause to be on the same line as the constructor.

[jbcoe]

Thanks for this!