Keeping the reference in sync.

[ehuss]

I think it is very difficult to keep the reference in sync with rustc. There are many obscure English statements throughout the reference asserting some behavior that have a risk of being invalidated in the future as rustc changes.

I'm not sure what's the best way to make it more robust. Every clause could be broken out into separate numbered sections (like C++ does), and then a test suite could be made that tries to cover as many clauses as reasonably possible.

[Havvy]

One thing we could do is make sure that test cases exist in rustc for each thing we discuss and put the test cases in comments near the prose.