Remove parenthesis surrounding the new loop index.
Perhaps add a comment (or correct me if I'm wrong ;)
(can Usage.Expression be something more complex?)
Usage.Expression can be:
-CXXOperatorCallExpr: "*it" or "container[i]"
-MemberExpr: "it->member" (we only replace "it->" with "elem." in this
The point is that all of them except the last one will be replaced by
"elem" (or any other identifier), so it will be a DeclRefExpr after the
change, and the parenthesis can always be removed. I can add a comment