Re: [Boost-users] multi_index new user question

I've got the following in my project // dummies needed for tagging struct by_name {}; struct by_id {}; struct by_vreg {}; // breaking this up into two steps makes things easier on the compiler, and produces readable? error messages struct ParmListIndices : multi_index::indexed_by < multi_index::sequenced<>, multi_index::ordered_unique, multi_index::const_mem_fun

, multi_index::ordered_non_unique, multi_index::const_mem_fun >,

-----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users- bounces@lists.boost.org] On Behalf Of Evan Carew Sent: Friday, December 30, 2005 1:03 PM To: boost-users@lists.boost.org Subject: [Boost-users] multi_index new user question

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The following is todays log of my efforts to get multi_index to work:

- ---First entry: I'm using boost multi index for the first time. I've managed to

multi_index::ordered_non_unique, multi_index::const_mem_fun > > {}; struct ParmList : multi_index::multi_index_container {}; typedef multi_index::nth_index::type ParmList_by_name; typedef multi_index::nth_index::type ParmList_by_id; typedef multi_index::nth_index::type ParmList_by_vreg; typedef pair ParmListResultPair; Note that I used structs to wrap a complicated multi_index instead of using typedefs. I learned this trick from a previous web discussion about multi_index. This relieves stress on the compiler (important for MSVC7.1 with maximum debugging turned on) and makes the error messages easier to read. I used typedef shortcuts for referring to the nth_index'es 'cause structs don't work there. This allowed me to write the following fairly simple looking code. Note the type of the variable "byName" and the iterator "f" below. ParmBase* ParmGroup::FindName(const string& name) { ParmList_by_name& byName = pParmList->get(); ParmList_by_name::iterator f = byName.find(name); return (f != byName.end()) ? *f : NULL; } These sorts of tricks make the code a little bit more readable. You can do a similar thing for your iterator pair in your range variable. -todd- populate

the container with my data & now I am trying to get the non-unique ordered index to work. Does anyone have a source example (not from the boost.multiindex tutorial please) used to get a list, set, whatever, of tuples from such a search on such an index?

Thanks, Evan Carew

P.S. G++ V3.4.2 Boost version 103300

- ---Second entry: Hmm... Looks like their list server is down. I am unable to register. <sigh>

- ---Third entry: Well, lets try this example source code:

typedef multi_index::multi_index_container< person, multi_index::indexed_by< multi_index::ordered_unique< multi_index::tag<voterid>, BOOST_MULTI_INDEX_MEMBER(person,unsigned long,voterid)>, multi_index::ordered_non_unique<

...

, multi_index::ordered_non_unique< multi_index::tag<resstreetnum>, BOOST_MULTI_INDEX_MEMBER(person,int,resstreetnum)> > people_set;

.....

int main(){ const people_set::nth_index<2>::type& resstreet_index=ps.get<2>(); pair range; range = resstreet_index.equal_range((*domoItor).first); }

The above code doesn't compile.

- ---Fourth entry: By changing the pair instance to:

pair::type::iterator, people_set::nth_index<2>::type::iterator> range;

I finally got it to compile. I managed this not by reading the tutorial for the library (the information isn't there) but from reading the rather prodigious code in multi_index.

- ---Fifth entry: Am I headed in the right direction, or is there specific interface

multi_index::tag<lastname>,BOOST_MULTI_INDEX_MEMBER(person,string,lastna me) that

defines the iterator types in a less painful/safe way?

Evan Carew