Howard Hinnant <howard.hinnant <at> gmail.com> writes:
On Jan 5, 2011, at 7:20 AM, bernardH wrote:
In my current code my algorithm is recursive: ...
The problem is I can't return a compile-time constant because of the recursion.
I must be missing something, but I fail to see the problem : couldn't you just use an #define EARLY_EXIT(condition) \ do{ \ result_type const result(condition); \ if(result) \ return result; \ }while(false) // to allow ; with typedef typename result_of< Function(typename std::iterator_traits<BidirectionalIterator>::value_type)
::type result_type; ? Untested code (*blush*) @http://paste.debian.net/103845/
And if this doesn't work, you could always have two separate implementations one for Callable returning void and one for Callable returning bool and use enable_if on the result_type to select the proper one, no ?
To complicate things, in some of the algorithms I wrap the Function with an adaptor on the way down in order to fancier things like reversible_permutation.
If my solution is correct, I do (want to :) )believe that it could be adapted.
The answer might depend upon if we get an equally performant next_* going. If we do, then I don't think the functor should return a bool to break: instead the client should use next_*. If we don't, then putting in the break feature means, at least to me, that there is no reason to use the next_* variant since it is always slower (even if only by a little).
Agreed.
Thanks for furthering these algorithms.
Thank *you* for your most excellent code. Best Regards, Bernard