Bruno Le Floch skrev 2012-08-21 17.51:
> to get the error.  The problem comes from indexing the \&  command when
> the \verbatimchar used by indexing macros is&.  Ideally, we could
> change the verbatim character depending on the function being indexed.
>   The same error occurs with one of the l3fp files IIRC, since&
> appears in a \begin{macro} argument.  Changing the \verbatimchar to
> something else would just be a temporary fix.

I must say I'm shocked that you're still using \verb in indices. This is 
certainly one of the cruftier parts of doc.sty, and generally something 
which is just begging for throwing weird errors at users down the line.

xdoc2.dtx shows how one can cleanly avoid this. It may "only" be half the 
age of doc.sty, but surely some of you should have looked at it. ;-)

Lars Hellström