Re: matrix and vector iterators

From: jcampbell3_at_[hidden]
Date: 2001-06-12 11:49:29

--- In boost_at_y..., Jeremy Siek <jsiek_at_r...> wrote:
> 
> One thing that we need to decide on is the interface for traversing
> vectors and matrices. I see a couple options:
> 
> 1. MTL-style iterators
> 
>   *i          // return a matrix/vector element
>   i.index()   // return the index of the element pointed to (for
vectors)
>   i.row()     // return the row index (for matrices)
>   i.colummn() // return the column indexn (for matrices)
Since the following:

  i.index(0) returns the index along "axis" 0 (row?)
  i.index(1) returns the index along "axis" 1 (col?)
  i.index(int n) returns index along "axis" n

would work for any rank array, I recommend it.  As another
alternative:

  i.axis(n)++ would increment the index along axis n
  i.axis(n).index() would return index along axis n

Of course in each of the above cases, the user could input
an n>rank, resulting in coredump.  Maybe the axis
method could be specialized on template<unsigned n>class Axis
to somehow avoid this.