Hello,
The review of Indexed Set library, written by Joaquín M López Muñoz starts today (March 20) and runs for 10 days.
Latest version (9.4) of the library is available on: http://groups.yahoo.com/group/boost/files/indexed_set.zip (328 kB)
Downloaded and installed it sucessfully.
What it is? indexed_set is generic, STL compliant container providing one or more views
I still regard these views more as indices, because they are populated at insertion time IIUC.
on its data. These views allow to use data sorted according to different criteria. Change in container data is automatically propagated into all views.
How many views and what ordering is applied is specified in declarative way, as template parameter.
This I like.
What it is good for? - it can replace multiple collections of data and hand-written code keeping them in sync. - it can replace standard containers (as std::set or std::list) if these may not meet future reqirements. - it can serve as basic for other libraries. For example RTL (relational tables library) may use indexed_set to hold its data.
To try it out I ported the example from http://www.cs.rpi.edu/~musser/stl-book/source/ex18-01.cpp.txt to use indexed_set<>. Port attached. I didn't see a performance penalty. But the test could be IO bound and I didn't profile.
Other features of indexed_set: - sorting can be performed on result of member function (similar to calculated indexes in RDBMS). - indexed_set can be used as 'wrapper' over other data structures, e.g you can see data in std::vector as being sorted in set-like structure (but without structures being synchronized). - many, many others ...
I miserably failed to define a composite unique key for my indexed_set. Should this be possible? One more question: is there an (easy?) way to iterate over the distinct values of an index (or to define the index as the set of distinct values of the related attribute(s))?
Future development: - planned functionality is described on its own page in documentation. - indexed_set may also implement access to its data in the same way as std::deque, with random O(1) access
I'd have to do much more homework to understand the current version.
History of the project: - it started as 'bimap' library more than year ago, - some two dozen iterations were released, - several Boost people expressed their interest or did suggest features.
Good that they did.
Boost-wide reusable parts of the library: - indexed_set includes (nearly verbatim) copy of Andrei Alexandresu ScopeGuard. It is intended as stop-gap until Boost wide library emerges. - maybe auto_space.hpp can be liften into utilities.
Hm.
Portability: - see document page for list of compilers and their issues - Can someone try to run tests under release mode of VC 6.5? We got different results with different machines.
Still somebody developing for that compiler? Incredible.
Word from the autor: "Thank you for reviewing indexed_set. There are several points, mostly concerning naming, that I'd like to be discussed during the review. You can find these at the URL
http://groups.yahoo.com/group/boost/files/indexed_set_review_notes.html
If you evaluate the library and deem it acceptable for Boost,
Yes, I do.
please walk the extra mile and express your opinions about the issues brought forward in the review notes. Naming issues are quite sensitive, and I'd like to reach as general a consensus as possible."
If Joaquín is going to invent indexed_map, too, then indexed_set is OK. Otherwise we seem to be working with something like an indexed_table or table IMHO. Namespace boost would be OK for me. Regular indices are OK, because I didn't need sequenced ones until now ;-). Ordered_(non)_unique would be OK to resolve the std:: name clash, but no strong preference here. No opinion regarding nth_index_type and update/modify/replace. No problem with header dependencies. Best regards, Joerg