1 | // Boost.Bimap |
2 | // |
3 | // Copyright (c) 2006-2007 Matias Capeletto |
4 | // |
5 | // Distributed under the Boost Software License, Version 1.0. |
6 | // (See accompanying file LICENSE_1_0.txt or copy at |
7 | // http://www.boost.org/LICENSE_1_0.txt) |
8 | |
9 | /// \file container_adaptor/detail/functor_bag.hpp |
10 | /// \brief Defines a EBO optimizacion helper for functors. |
11 | |
12 | #ifndef BOOST_BIMAP_CONTAINER_ADAPTOR_DETAIL_FUNCTOR_BAG_HPP |
13 | #define BOOST_BIMAP_CONTAINER_ADAPTOR_DETAIL_FUNCTOR_BAG_HPP |
14 | |
15 | #if defined(_MSC_VER) |
16 | #pragma once |
17 | #endif |
18 | |
19 | #include <boost/config.hpp> |
20 | |
21 | #if defined(BOOST_MSVC) |
22 | // This bogus warning will appear when add_const is applied to a |
23 | // const volatile reference because we can't detect const volatile |
24 | // references with MSVC6. |
25 | # pragma warning(push) |
26 | # pragma warning(disable:4181) |
27 | // warning C4181: qualifier applied to reference type ignored |
28 | #endif |
29 | |
30 | #include <boost/mpl/placeholders.hpp> |
31 | |
32 | #include <boost/type_traits/add_reference.hpp> |
33 | #include <boost/type_traits/is_base_of.hpp> |
34 | |
35 | #include <boost/mpl/inherit_linearly.hpp> |
36 | #include <boost/mpl/inherit.hpp> |
37 | |
38 | namespace boost { |
39 | namespace bimaps { |
40 | namespace container_adaptor { |
41 | namespace detail { |
42 | |
43 | /// \brief EBO optimizacion helper for functors |
44 | /** |
45 | |
46 | This class is a generalization of a helper class explained in an article by |
47 | Nathan C. Myers.\n |
48 | See it at \link http://www.cantrip.org/emptyopt.html |
49 | **/ |
50 | |
51 | template < class Data, class FunctorList > |
52 | struct data_with_functor_bag : |
53 | |
54 | public mpl::inherit_linearly< |
55 | |
56 | FunctorList, |
57 | mpl::if_< is_base_of< mpl::_2, mpl::_1 >, |
58 | // { |
59 | mpl::_1, |
60 | // } |
61 | // else |
62 | // { |
63 | mpl::inherit< mpl::_1, mpl::_2 > |
64 | // } |
65 | > |
66 | |
67 | >::type |
68 | { |
69 | Data data; |
70 | |
71 | data_with_functor_bag() {} |
72 | |
73 | data_with_functor_bag(BOOST_DEDUCED_TYPENAME add_reference<Data>::type d) |
74 | : data(d) {} |
75 | |
76 | template< class Functor > |
77 | Functor& functor() |
78 | { |
79 | return *(static_cast<Functor*>(this)); |
80 | } |
81 | |
82 | template< class Functor > |
83 | const Functor& functor() const |
84 | { |
85 | return *(static_cast<Functor const *>(this)); |
86 | } |
87 | }; |
88 | |
89 | } // namespace detail |
90 | } // namespace container_adaptor |
91 | } // namespace bimaps |
92 | } // namespace boost |
93 | |
94 | #if defined(BOOST_MSVC) |
95 | # pragma warning(pop) |
96 | #endif |
97 | |
98 | #endif // BOOST_BIMAP_CONTAINER_ADAPTOR_DETAIL_FUNCTOR_BAG_HPP |
99 | |
100 | |
101 | |