]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
1 | //---------------------------------------------------------------------------// |
2 | // Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com> | |
3 | // | |
4 | // Distributed under the Boost Software License, Version 1.0 | |
5 | // See accompanying file LICENSE_1_0.txt or copy at | |
6 | // http://www.boost.org/LICENSE_1_0.txt | |
7 | // | |
8 | // See http://boostorg.github.com/compute for more information. | |
9 | //---------------------------------------------------------------------------// | |
10 | ||
11 | #ifndef BOOST_COMPUTE_LAMBDA_PLACEHOLDERS_HPP | |
12 | #define BOOST_COMPUTE_LAMBDA_PLACEHOLDERS_HPP | |
13 | ||
14 | #include <boost/mpl/has_xxx.hpp> | |
15 | ||
16 | #include <boost/compute/lambda/context.hpp> | |
17 | #include <boost/compute/lambda/result_of.hpp> | |
18 | ||
19 | namespace boost { | |
20 | namespace compute { | |
21 | namespace lambda { | |
22 | ||
23 | namespace mpl = boost::mpl; | |
24 | namespace proto = boost::proto; | |
25 | ||
26 | // lambda placeholders | |
27 | expression<proto::terminal<placeholder<0> >::type> const _1; | |
28 | expression<proto::terminal<placeholder<1> >::type> const _2; | |
29 | expression<proto::terminal<placeholder<2> >::type> const _3; | |
30 | ||
31 | namespace detail { | |
32 | ||
33 | BOOST_MPL_HAS_XXX_TRAIT_DEF(result_type) | |
34 | ||
35 | template<class T, bool HasResultType> | |
36 | struct terminal_type_impl; | |
37 | ||
38 | template<class T> | |
39 | struct terminal_type_impl<T, true> | |
40 | { | |
41 | typedef typename T::result_type type; | |
42 | }; | |
43 | ||
44 | template<class T> | |
45 | struct terminal_type_impl<T, false> | |
46 | { | |
47 | typedef T type; | |
48 | }; | |
49 | ||
50 | template<class T> | |
51 | struct terminal_type | |
52 | { | |
53 | typedef typename terminal_type_impl<T, has_result_type<T>::value>::type type; | |
54 | }; | |
55 | ||
56 | } // end detail namespace | |
57 | ||
58 | // result_of placeholders | |
59 | template<class Args> | |
60 | struct result_of<expression<proto::terminal<placeholder<0> >::type>, Args, proto::tag::terminal> | |
61 | { | |
62 | typedef typename boost::tuples::element<0, Args>::type arg_type; | |
63 | ||
64 | typedef typename detail::terminal_type<arg_type>::type type; | |
65 | }; | |
66 | ||
67 | template<class Args> | |
68 | struct result_of<expression<proto::terminal<placeholder<1> >::type>, Args, proto::tag::terminal> | |
69 | { | |
70 | typedef typename boost::tuples::element<1, Args>::type arg_type; | |
71 | ||
72 | typedef typename detail::terminal_type<arg_type>::type type; | |
73 | }; | |
74 | ||
75 | template<class Args> | |
76 | struct result_of<expression<proto::terminal<placeholder<2> >::type>, Args, proto::tag::terminal> | |
77 | { | |
78 | typedef typename boost::tuples::element<2, Args>::type arg_type; | |
79 | ||
80 | typedef typename detail::terminal_type<arg_type>::type type; | |
81 | }; | |
82 | ||
83 | } // end lambda namespace | |
84 | ||
85 | // lift lambda placeholders up to the boost::compute namespace | |
86 | using lambda::_1; | |
87 | using lambda::_2; | |
88 | using lambda::_3; | |
89 | ||
90 | } // end compute namespace | |
91 | } // end boost namespace | |
92 | ||
93 | #endif // BOOST_COMPUTE_LAMBDA_PLACEHOLDERS_HPP |