Boost (Notepad++) flavor
Add support for the notepad++ style of regexes
Notepad++ actually uses Boost regex. From my testing, it seems that it doesn't use u32regex, so Unicode character classes (\p{...}) are not available.
Anyway, Boost and PCRE regex are quite close. Unless you are using equivalence class ([=...=]) and Unicode character classes, the rest are quite similar.
i can attest to backtracking control verbs NOT being supported in Notepad++, unfortunately :disappointed:
The current README.md file suggests that it's using Boost 1.5.5, which doesn't seem to support backtracking control verb. It really depends on the library version.
Boost Regex also supports conditionals in the Substitution. (At least I couldn't figure out if it is possible in one of the existing flavors) Also, {} have to be escaped always except inside []