Re: Possible improvement in next_permutation implementation

[Paolo Carlini <pcarlini at suse dot de>]

Hi David,

and many thanks for your feedback. By the way, months ago I mentioned 
many times in private talk with people working at CERN that I was 
"disappointed" by the lack of feedback from all the power users working 
there... Good news, then ;)
> I wonder whether it would be possible to make an implementation of the 
> standard library method closer to what the gsl algorithm does. The 
> three algorithms are intrinsically the same one, but the way they have 
> been implemented differ in the small details, and that is what makes 
> the difference in time. I also wonder, what is the reason to have 
> implemented the algorithm this way. There may be reasons I do not see 
> because of my poor knowledge of the implementation of the library.
I will look into it, but I suppose there aren't very deep explanations, 
assuming the basic algorithm is the same, of course, only historical 
reasons, the usual ones, lack of feedback (see above)... As I said, I 
will look into the details of the issue, but in the meanwhile, if you 
feel like providing additional help (I don't know, pseudo-code, 
whatever), you are more than welcome, of course.

Paolo.

PS Last saturday, I visited ATLAS!