Re: [Boost-users] [multiindex] [bind] Conversion loses qualifiers

Nebojsa Simic wrote:

Hello all,

First of all, thanks for a wonderful library, it is a pleasure to work with...

However I ran into some problems and I can not find the answers either on the Internet nor on this mailing list. The problem at hand concerns the multiindex container and bind.

I have a class with the following member:

class Statistics { public: void addStats ( double val, int tick ); }

and a container:

typedef multi_index_container< Statistics, indexed_by , ordered_non_unique< member > >

...

StatisticsMap;

StatisticsMap m_statistic;

indexed by :

typedef StatisticsMap::nth_index<1>::type StatisticsByResponse;

somewhere in code i try to do this :

std::pairStatisticsMap::iterator,bool result = m_statistic.insert( Statistics( response, value, tick ) );

StatisticsByResponse& idxResponse = m_statistic.get<1>(); StatisticsByResponse::iterator it = m_statistic.project<1>(result.first );

the problem comes when I try to update the statistics by using :

for_each( it , idxResponse.end() , boost::bind( &Statistics::addStats, ::_1, val, tick ) );

Ok, the elements in the container are constant and may not be changed through iterators. For multiindex container the modify method must be used to change them. So I changed the last line to : boost::function fnAddStats = boost::bind( &Statistics::addStats, ::_1, val, tick ); for_each( it , idxResponse.end() , boost::bind( &StatisticsByResponse::modify, boost::ref(idxResponse), ::_1, fnAddStats ) ); but it still does not compile (problem with boost::bind "wrong number of arguments"). the call : idxResponse.modify( it, fnAddStats ); works, so the problem is not the first bind, but the one in for_each. -- Nebojsa Simic