table: better ContentStore findRightmost algorithm
refs #2254
Change-Id: Ib8f473f0cce1a1636b600a98494292499d71972e
diff --git a/core/algorithm.hpp b/core/algorithm.hpp
new file mode 100644
index 0000000..5dc9dbb
--- /dev/null
+++ b/core/algorithm.hpp
@@ -0,0 +1,58 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015, Regents of the University of California,
+ * Arizona Board of Regents,
+ * Colorado State University,
+ * University Pierre & Marie Curie, Sorbonne University,
+ * Washington University in St. Louis,
+ * Beijing Institute of Technology,
+ * The University of Memphis.
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef NFD_CORE_ALGORITHM_HPP
+#define NFD_CORE_ALGORITHM_HPP
+
+#include "common.hpp"
+#include <boost/concept/requires.hpp>
+
+namespace nfd {
+
+/** \brief finds the last element satisfying a predicate
+ * \tparam It BidirectionalIterator
+ * \tparam Pred UnaryPredicate
+ *
+ * \return Iterator to the last element satisfying the condition,
+ * or \p last if no such element is found.
+ *
+ * Complexity: at most \p last-first invocations of \p p
+ */
+template<typename It, typename Pred>
+BOOST_CONCEPT_REQUIRES(
+ ((boost::BidirectionalIterator<It>))
+ ((boost::UnaryPredicate<Pred, typename std::iterator_traits<It>::value_type>)),
+ (It)
+)
+find_last_if(It first, It last, Pred p)
+{
+ std::reverse_iterator<It> firstR(first), lastR(last);
+ auto found = std::find_if(lastR, firstR, p);
+ return found == firstR ? last : std::prev(found.base());
+}
+
+} // namespace nfd
+
+#endif // NFD_CORE_ALGORITHM_HPP