[boost] Re: Interest in multiindex_set?(again)

From: Beman Dawes (bdawes_at_[hidden])
Date: 2003-07-07 15:49:18

At 03:15 PM 7/7/2003, Joaquín Mª López Muñoz wrote:

 >Please find some preliminary documentation for multiindex_set
 >at:
 >
 >http://groups.yahoo.com/group/boost/files/multiindex.zip

Hi Joaquín,

I took a quick look at multiindex.html, and found it quite interesting. It 
appears to meet a common need. Here are some specific (but not carefully 
thought out) comments:

*  The "multiindex_set" name seems awkward to me. Maybe "indexed_set" or 
"set_index"?

*  It seems safer to me for the default to be indexes that are unique.

*  Separating the specification of uniqueness from the list of indices 
seems like a recipe for mistakes, particularly during maintenance. Is it 
possible to combine uniqueness specification with the index tuple? Perhaps 
your example could look like this:

   typedef boost::multiindex::multiindex_set<
     employee,
     boost::tuple< employee::comp_id,
                   multi< employee::comp_name >,
                   employee_name::comp_ssnumber >,
                 > employee_set;

or this:

   typedef boost::multiindex::multiindex_set<
     employee,
     boost::tuple< unique< employee::comp_id >,
                   non_unique< employee::comp_name >,
                   unique< employee_name::comp_ssnumber > >,
                 > employee_set;

* The need for an update member function also comes up in other non-STL 
containers like B-trees, so don't worry that it is an add-on.

* It isn't clear (or I missed it) if iterators are always logically 
const-iterators or not. In other words, could your example have been 
written like this?

   typedef index_type<employee_set,1>::type employee_set_by_name;
   employee_set_by_name& i=es.get<1>();

   employee_set_by_name::iterator it=i.find("Anna Jones");
   it->name="Anna Smith"; //she just got married to Calvin Smith

Anyhow, I'm glad to see you working on this, and hope you will continue 
with it.

--Beman