1 /*
2 Copyright (c) Marshall Clow 2017.
3
4 Distributed under the Boost Software License, Version 1.0. (See accompanying
5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 */
7
8 /// \file transform_reduce.hpp
9 /// \brief Combine the (transformed) elements of a sequence (or two) into a single value.
10 /// \author Marshall Clow
11
12 #ifndef BOOST_ALGORITHM_TRANSFORM_REDUCE_HPP
13 #define BOOST_ALGORITHM_TRANSFORM_REDUCE_HPP
14
15 #include <functional> // for std::plus
16 #include <iterator> // for std::iterator_traits
17
18 #include <boost/config.hpp>
19 #include <boost/range/begin.hpp>
20 #include <boost/range/end.hpp>
21 #include <boost/range/value_type.hpp>
22
23 namespace boost { namespace algorithm {
24
25 template<class InputIterator, class OutputIterator, class T, class BinaryOperation>
26 OutputIterator inclusive_scan(InputIterator first, InputIterator last,
27 OutputIterator result, BinaryOperation bOp, T init)
28 {
29 for (; first != last; ++first, (void) ++result) {
30 init = bOp(init, *first);
31 *result = init;
32 }
33 return result;
34 }
35
36
37 template<class InputIterator, class OutputIterator, class BinaryOperation>
38 OutputIterator inclusive_scan(InputIterator first, InputIterator last,
39 OutputIterator result, BinaryOperation bOp)
40 {
41 if (first != last) {
42 typename std::iterator_traits<InputIterator>::value_type init = *first;
43 *result++ = init;
44 if (++first != last)
45 return boost::algorithm::inclusive_scan(first, last, result, bOp, init);
46 }
47
48 return result;
49 }
50
51 template<class InputIterator, class OutputIterator>
inclusive_scan(InputIterator first,InputIterator last,OutputIterator result)52 OutputIterator inclusive_scan(InputIterator first, InputIterator last,
53 OutputIterator result)
54 {
55 typedef typename std::iterator_traits<InputIterator>::value_type VT;
56 return boost::algorithm::inclusive_scan(first, last, result, std::plus<VT>());
57 }
58
59 }} // namespace boost and algorithm
60
61 #endif // BOOST_ALGORITHM_TRANSFORM_REDUCE_HPP
62