[reanimus]

> I am not making things up when I say that the very first question I had about how to use this module, either is not answered, or I couldn't find the answer. That question was "what regular expression syntax is supported?". This is such a fundamental question, yet there is no answer provided.

The main page for the documentation answers that question: https://docs.rs/regex/1.11.1/regex/index.html

It even says "If you just want API documentation, then skip to the Regex type", which is what you were linked to before.