1/*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3 Copyright (c) 2005-2006 Dan Marsden
4 Copyright (c) 2018 Kohei Takahashi
5
6 Distributed under the Boost Software License, Version 1.0. (See accompanying
7 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
8==============================================================================*/
9#if !defined(BOOST_FUSION_VALUE_AT_IMPL_20061101_0745)
10#define BOOST_FUSION_VALUE_AT_IMPL_20061101_0745
11
12#include <boost/fusion/support/config.hpp>
13#include <boost/fusion/sequence/intrinsic/value_at.hpp>
14#include <boost/utility/result_of.hpp>
15
16namespace boost { namespace fusion {
17 struct transform_view_tag;
18 struct transform_view2_tag;
19
20 namespace extension
21 {
22 template<typename Tag>
23 struct value_at_impl;
24
25 template<>
26 struct value_at_impl<transform_view_tag>
27 {
28 template<typename Seq, typename N>
29 struct apply
30 {
31 typedef typename Seq::transform_type F;
32 typedef typename result_of::value_at<typename Seq::sequence_type, N>::type value_type;
33 typedef typename boost::result_of<F(value_type)>::type type;
34 };
35 };
36
37 template<>
38 struct value_at_impl<transform_view2_tag>
39 {
40 template<typename Seq, typename N>
41 struct apply
42 {
43 typedef typename Seq::transform_type F;
44 typedef typename result_of::value_at<typename Seq::sequence1_type, N>::type value1_type;
45 typedef typename result_of::value_at<typename Seq::sequence2_type, N>::type value2_type;
46 typedef typename boost::result_of<F(value1_type, value2_type)>::type type;
47 };
48 };
49 }
50}}
51
52#endif
53