simple-rust-tests/__misc/fancy-regex/README.md

https://github.com/fancy-regex/fancy-regex

A Rust library for compiling and matching regular expressions. It uses a hybrid regex implementation designed to support a relatively rich set of features. In particular, it uses backtracking to implement "fancy" features such as look-around and backtracking, which are not supported in purely NFA-based implementations (exemplified by RE2, and implemented in Rust in the regex crate).