Scope enum StructureState

[Brett208]

A couple of interesting changes were required to prevent some casting. I think it all improves readability.

This changeset will likely cause merge conflict in other uncommitted branches due to the prolific use of StructureState.

I wasn't sure it was best to move StructureState out of Structure.h, but I didn't think it was wise for Structure.h to reference Common.h and Common.h to reference Structure.h at the same time. And I'm not sure you are allowed to forward declare enum class? If this move isn't palatable, maybe there is an alternate solution.

[DanRStevens]

I like the function signature changes to avoid casting. That was a good call.

Cyclic dependencies are probably best avoided with the header files. Assuming they have #pragma once, or header guards, it shouldn't matter, but still best to avoid it. With that said, I do kind of want to move away from dumping lots of different stuff in Common.h. I figure Structure related enum definitions are probably better suited to being part of the Structure class. Perhaps something we can look into at a later time.

I believe enum class can be forward declared. In particular, an enum class always has a base type, either implied, or explicitly specified. That means the compiler will always know how much space to allocate for it. That wasn't the case for regular enum definitions, when a base type wasn't specified, as the size could depend on the defined values.

[Brett208]

Ah right. I had mixed up which could be forward declared. I'll try to forward declare before merging.

[Brett208]

Apparently you cannot forward declare an enum class that is the member of a class...

[Brett208]

Tagging #319

[DanRStevens]

Huh, Interesting. Seems the scope nesting does pose problems for enum forward declarations. I had to try it just to see what happens. And of course, check StackOverflow 😁
Is in-class enum forward declaration possible?

Apparently it really isn't possible.

Anyway, looks like you found a pretty good solution.