boost::xpressive::_ — Matches any one character.
// In header: <boost/xpressive/regex_primitives.hpp> unspecified _;
Match any character, similar to '.' in perl syntax with the /s modifier. '_' matches any one character, including the newline.
To match any character except the newline, use ~_n
![[Note]](../../../../doc/src/images/note.png)