Dear Thorsten, On Thu, 2009-02-26 at 14:38 +0100, Thorsten Ottosen wrote:
Rogier van Dalen skrev:
I still suggest removing any operation that uses output iterators (except "copy"), and just use lazy versions.
This you want to keep because of std::ostream_iterator?
I think output iterators can be useful, for example, in writing to files or forms of linear storage. If C++ had coroutines, output iterators would have been more generally useful. But algorithms that take output iterators often force the user to write to a temporary. They combine (in my mind) two operations: (1) processing or producing data, and (2) writing the output out to a sink. (1) can be written with lazy ranges; (2) can be written using copy(). I think all current STL algorithms that take output iterators could be written as copy()ing a lazy range to the output iterator. Looking at the "Mutating algorithms" section of the RangeEx docs, I believe that goes for copy_backward(), fill(), generate(), merge(), transform(), and the set algorithms. For efficiency, some combinations of copy() with lazy ranges could forward to STL implementations. I'd be happy to help out with lazy set algorithms since I've got implementations lying around. Cheers, Rogier