The following command should output the string "
:echo matchstr('test', '\(\?<=e\).*')
However, it leads to the error mentioned in the title. Reading
:h E866 didn't help much. I also tried changing the escapes in the expression (i.e.
\(?\<=e\).*, etc...), but to no avail.
What's wrong with my usage of
?<=, and how may I fix it?