Current draft of "C++ Identifier Syntax using Unicode Standard Annex 31"
https://github.com/steve-downey/papers/blob/master/D1949R1.md
<https://slack-redir.net/link?url=https%3A%2F%2Fgithub.com%2Fsteve-downey%2Fpapers%2Fblob%2Fmaster%2FD1949R1.md>
Final format will by html, produced by MPark's wg21 tool. Expanded
discussion of everything, added explicit character lists, added authors,
per last telecon.