[Boost-users] [MultiIndex] Key extraction from a base member

From: Bruno Martínez (br1_at_[hidden])
Date: 2005-10-19 15:46:37

Hi.

I have the following problem with MultiIndex.  For

struct Base {
        int id;
};

struct Der : Base {
};

I can't make a key extractor.

This way

typedef multi_index_container<
Der,
indexed_by<
ordered_unique<member<Der, int, &Der::id> >
>Set;

doesn't work because &Der::id is of type pointer to member of Base.

This other

typedef multi_index_container<
Der,
indexed_by<
ordered_unique<member<Base, int, &Base::id> >
>Set;

doesn't work because of the ChainedPtr overloads in member.

I tried casting &Der::id to the appropiate type, but couldn't make it  
work.  Maybe the solution is to put some enable_ifs in member.

Regards,
Bruno