On 03/12/08 07:40, Max Motovilov wrote:
Larry Evans wrote: [snip] Not quite like that, and I knew my "description" would end up being misleading :( -- so much for posting after a long working day.
Input:
list< list< A0_0, A0_1 >, list< A1_0, A1_1 >
Output:
list< list< A0_0, A1_0 >, list< A0_0, A1_1 >, list< A0_1, A1_0 >, list< A0_1, A1_1 >
I think this is what you meant to write above.
Yep. Hadn't had my first cup coffee yet ;)
Yes, it is an outer product, or direct product, or Cartesian product: C(A,B)={ [x,y] | for each x in A and y in B }
And of course if any of the sequences is empty, the output is also empty. Requires a separate rule, incidentally.
In that case, then yes, it's been at least considered. The _C++ Template Metaprogramming_ book has it as an exercise, exercise 7-8 and calls it crossproduct_view. A solution is posted here: http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?CPPTM_Answers... It would be interesting to compare the two solutions. The exercise just specified 2 input sequences whereas your's allows (I guess) any n>0 number of input sequences.