2010/1/27 Stewart, Robert <Robert.Stewart@sig.com>:
Joachim Faulhaber wrote:
That's an excellent question. I, too, foresaw its usefulness in assertions. I can imagine those doing DBC would like it, too. However, I can imagine examining file, network, or user input to ensure the data fits some ordering criteria, too.
. . . more of the (initially) asserting-the-invariant type of use.
The latter were not, in my mind, assertion uses, but rather run-time, production code tests to determine whether to accept or reject an input. ok.
I've looked in boost_1_41_0 . There are four (4) uses of is_sorted, all in asserts in graph\distributed\connected_components.hpp
Because folks will continue to use C++98/03 for some time, it is reasonable for Boost to provide a fallback for what's to come. Consequently, there's room yet to put this predicate into Boost. ok.
Remains the question, if the variants of is_[strictly_]{in_,de_}creasing are to be added as algorithms, which conjures up another intersting question:
Are there criteria to be fulfilled to maintain the minimality of a set of free algorithms?
I understand the desire to keep the set small enough to be manageable,
I think the clearness of the library interfaces is very important and the quest for criteria and guidelines is helpful.
but it should be large enough to avoid the need to repeat (and rediscover) common recipes. Are those four predicates sufficiently useful to justify being documented, tested, and maintained in Boost? If not, they can be illustrated as examples for use of is_sorted.
I'd prefer the latter. Good night from (freezing) Europe Joachim