[Boost-users] fusion: work of 4 sequences at the same time

Subject: [Boost-users] fusion: work of 4 sequences at the same time
From: Hicham Mouline (hicham_at_[hidden])
Date: 2010-02-18 12:37:41

Hi,

I am trying to apply fusion::for_each on a sequence, but inside the unary
functor applied to each element, I need to know the index of the element in
question, because I need to extract elements with the same index from other
sequences.

fusion::vector<...> fseq1;
fusion::vector<...> fseq2;
fusion::vector<...> fseq3;
fusion::vector<...> fseq4;

fusion::for_each( fseq1, functor<...>(fseq2, fseq3, fseq4) );

template <typename Seq2, typename Seq3, typename Seq4)
struct functor {
  /// ctor

  template <typename T>
  void operator()( const T& t) const
  {
      /// find out index of t in fseq1,  
      /// use elements from fseq2,3,4 at the same index
  }
};

I could use boost::fusion::find to get an iterator and then get its index,
but this doesn not look clean,

Any ideas,

Rds,