id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
3873,Promote Existing is_sorted Algorithm Detail to First-class Template / Track C++1x N3000 is_sorted{_until},gerickson@…,John Maddock,"This is in reference to the long thread at:

    http://lists.boost.org/Archives/boost/2010/01/161121.php

The original proposal was as follows:

	The creasing algorithm templates define four template functions for 
	determining the order properties of sequences, specifically: 
	
	    * Increasing 
	    * Decreasing 
	    * Strictly Increasing 
	    * Strictly Decreasing 
	
	The implementation is a fairly trivial composition of the STL adjacent_find, not2 and {greater,less,greater_equal,less_equal}. 
	For the purposes of sequence ordering validation, using these templates is more efficient and straightforward than creating a temporary, sorted version of some sequence and comparing it against the original sequence. 
	
	Example: 
	        bool 
	        CheckPoints(const Points & inPoints) 
	        { 
	            const bool strictlyIncreasing = is_strictly_increasing(inPoints.begin(), inPoints.end()); 
	
	            if (!strictlyIncreasing) { 
	                cerr << ""Points must be in increasing order with "" 
	                        ""no duplicate values."" 
	                     << endl; 
	            } 
	
	            return strictlyIncreasing; 
	        } 
	
	The review files are available in both Sandbox and Vault: 
	
	Sandbox: 
	
		boost/algorithm/creasing.hpp 
		libs/algorithm/creasing/example/creasing_ex.cpp 
		libs/algorithm/creasing/example/Jamfile 
		libs/algorithm/creasing/test/creasing_test.cpp 
		libs/algorithm/creasing/test/Jamfile.v2 
	
	Vault: 
	
		http://www.boostpro.com/vault/index.php?action=downloadfile&filename=creasing.zip&directory=Algorithms 

However, it was since discovered that:

    boost/detail/algorithm.hpp

has an implementation of is_sorted that more than meets the requirements of the original proposal.

Further, it was discovered that the current N3000 draft of C++0x (nay, C++1x) has is_sorted and is_sorted_until algorithms that also meet/exceed the original proposal requirements:

    http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n3000.pdf

So, this ticket requests:

1) Promote is_sorted from boost/detail/algorithm.hpp to boost/algorithm/sorted.hpp such that it is implied ""Yes, you can use this template. It is maintained and not just an implementation detail subject to change/disappearance.""

2) Better yet, update the implementation to include is_sorted_until proposed in C++1x N3000.

It'll be a long time until before compilers widely support C++1x. Having a boost-equivalent implementation until then would be great.",Feature Requests,closed,To Be Determined,graph,Boost Development Trunk,Problem,wontfix,,giecrilj@…