Added is_partitioned_until

* Fixed doxygen comment in is_partitioned algorithm.

include/boost/algorithm/cxx11/is_partitioned.hpp

@@ -39,7 +39,7 @@ bool is_partitioned ( InputIterator first, InputIterator last, UnaryPredicate p
 }
 
 /// \fn is_partitioned ( const Range &r, UnaryPredicate p )
-/// \brief Generates an increasing sequence of values, and stores them in the input Range.
+/// \brief Tests to see if a sequence is partitioned according to a predicate
 /// 
 /// \param r        The input range
 /// \param p        The predicate to test the values with

include/boost/algorithm/is_partitioned_until.hpp

@@ -0,0 +1,61 @@
+/*
+   Copyright (c) Alexander Zaitsev 2017.
+
+   Distributed under the Boost Software License, Version 1.0. (See accompanying
+   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/// \file  is_partitioned_until.hpp
+/// \brief Tell if a sequence is partitioned
+/// \author Alexander Zaitsev
+
+#ifndef BOOST_ALGORITHM_IS_PARTITIONED_UNTIL_HPP
+#define BOOST_ALGORITHM_IS_PARTITIONED_UNTIL_HPP
+
+#include <boost/range/begin.hpp>
+#include <boost/range/end.hpp>
+
+namespace boost { namespace algorithm {
+
+/// \fn is_partitioned_until ( InputIterator first, InputIterator last, UnaryPredicate p )
+/// \brief Tests to see if a sequence is partitioned according to a predicate
+///
+/// \param first    The start of the input sequence
+/// \param last     One past the end of the input sequence
+/// \param p        The predicate to test the values with
+///
+/// \note Returns the first iterator 'it' in the sequence [first, last) for which is_partitioned(first, it, p) is false.
+///     Returns last if the entire sequence is partitioned.
+///     Complexity: O(N).
+template <typename InputIterator, typename UnaryPredicate>
+InputIterator is_partitioned_until ( InputIterator first, InputIterator last, UnaryPredicate p )
+{
+//  Run through the part that satisfy the predicate
+    for ( ; first != last; ++first )
+        if ( !p (*first))
+            break;
+//  Now the part that does not satisfy the predicate
+    for ( ; first != last; ++first )
+        if ( p (*first))
+            return first;
+    return last;
+}
+
+/// \fn is_partitioned_until ( const Range &r, UnaryPredicate p )
+/// \brief Tests to see if a sequence is partitioned according to a predicate
+///
+/// \param r        The input range
+/// \param p        The predicate to test the values with
+///
+/// \note Returns the first iterator 'it' in the sequence [first, last) for which is_partitioned(first, it, p) is false.
+///     Returns last if the entire sequence is partitioned.
+///     Complexity: O(N).
+template <typename Range, typename UnaryPredicate>
+typename boost::range_iterator<Range>::type is_partitioned_until ( const Range &r, UnaryPredicate p )
+{
+    return boost::algorithm::is_partitioned_until (boost::begin(r), boost::end(r), p);
+}
+
+}}
+
+#endif  // BOOST_ALGORITHM_IS_PARTITIONED_UNTIL_HPP