AutoIndex is a tool for taking the grunt work out of indexing a Quickbook/Boostbook/Docbook document that describes C/C++ code.

Traditionally, in order to index a Docbook document you would have to manually add a large amount of <indexterm> markup: in fact one <indexterm> for each occurance of each term to be indexed.

Instead AutoIndex will scan one or more C/C++ header files and extract all the function, class, macro and typedef names that are defined by those headers, and then insert the <indexterm>'s into the XML document for you.

AutoIndex creates index entries as follows - for each occurance of each search term, it creates two index entries - one has the search term as the primary index key and the title of the section it appears in as a subterm, the other has the section title as the main index entry and the search term as the subentry. Thus the user has two chances to find what their looking for, based upon either the section name or the function, class, macro or typedef name.

So for example in Boost.Math the class name students_t_distribution has a primary entry that lists all sections it appears in:

Then those sections also have primary entries, which list all the search terms those sections contain:

Of course these automated index entries may not be quite what you're looking for: often you'll get a few spurious entries, a few missing entries, and a few entries where the section name used as an index entry is less than ideal. So AutoIndex provides some powerful regular expression based rules that allow you to add, remove, constrain, or rewrite entries. Normally just a few lines in AutoIndex's script file are enough to tailor the output to match the authors expectations.

AutoIndex also supports multiple indexes (as does Docbook), and since it knows which search terms are function, class, macro or typedef names, it can add the necessary attritubes to the XML so that you can have separate indexes for each of these different types. These specialised indexes only contain entries for the function, class, macro or typedef names, section names are never used as primary index terms here, unlike the main "include everything" index.

Finally, while the Docbook XSL stylesheets create nice indexes complete with page numbers for PDF output, the HTML indexes look a lot less good, as these use section titles in place of page numbers... but as AutoIndex uses section titles as index entries this leads to a lot of repetition, so as an alternative AutoIndex can be instructed to construct the index itself. This is faster than using the XSL stylesheets, and now each index entry is a hyperlink to the approprate section:

With internal index generation there is also a helpful navigation bar at the start of each Index: