Re: [boost] Proposed: a new sequence adapter for MPL (product_view)

From: Larry Evans (cppljevans_at_[hidden])
Date: 2008-03-15 10:55:58

On 03/15/08 08:26, Larry Evans wrote:
> On 03/12/08 20:21, Max Motovilov wrote:
> [snip]
>> Second, while recursive implementation is very similar to the iterative, 
>> it still generates the combinations in reverse order :)  Not important 
>> for applications I can think of, but still.
> 
> *Maybe* one application would be matrix multiplication where the
> shape is known but the values aren't.  Then the outer product
> of n domains, where each domain is range_c<0,size_rank> where
> size_rank is the size of the rank-th dimension of the array,
> would produce an matrix of the indices's into row of the
> left matrix and column of the right matrix.... Sorry, that
> explanation is getting too complicated, but anyway, the
> order would be important in this case.

Also, instead of a flatten'ed list, I think the cross_product
should produce a nested list where the depth of nesting is
the number of domains.  IOW, given two domains, a matrix
would be produced.  Given n-domains, an array of rank n
would be produced.  At least I *think* that's what apl
does.