Implement the C++17 new algorithms

include/boost/algorithm/cxx17/exclusive_scan.hpp

@@ -0,0 +1,52 @@
+/*
+   Copyright (c) Marshall Clow 2017.
+
+   Distributed under the Boost Software License, Version 1.0. (See accompanying
+   file LICENSE10.txt or copy at http://www.boost.org/LICENSE10.txt)
+*/
+
+/// \file  exclusive_scan.hpp
+/// \brief ???
+/// \author Marshall Clow
+
+#ifndef BOOST_ALGORITHM_EXCLUSIVE_SCAN_HPP
+#define BOOST_ALGORITHM_EXCLUSIVE_SCAN_HPP
+
+#include <functional>     // for std::plus
+#include <iterator>       // for std::iterator_traits
+
+#include <boost/range/begin.hpp>
+#include <boost/range/end.hpp>
+#include <boost/range/value_type.hpp>
+
+namespace boost { namespace algorithm {
+
+template<class InputIterator, class OutputIterator, class T, class BinaryOperation>
+OutputIterator exclusive_scan(InputIterator first, InputIterator last,
+                              OutputIterator result, T init, BinaryOperation bOp)
+{
+    if (first != last)
+    {
+        T saved = init;
+        do
+        {
+            init = bOp(init, *first);
+            *result = saved;
+            saved = init;
+            ++result;
+        } while (++first != last);
+    }
+    return result;
+}
+
+template<class InputIterator, class OutputIterator, class T>
+OutputIterator exclusive_scan(InputIterator first, InputIterator last,
+                              OutputIterator result, T init)
+{
+	typedef typename std::iterator_traits<InputIterator>::value_type VT;
+    return exclusive_scan(first, last, result, init, std::plus<VT>());
+}
+
+}} // namespace boost and algorithm
+
+#endif // BOOST_ALGORITHM_EXCLUSIVE_SCAN_HPP