1// Boost.Range library
2//
3// Copyright Neil Groves 2010. Use, modification and
4// distribution is subject to the Boost Software License, Version
5// 1.0. (See accompanying file LICENSE_1_0.txt or copy at
6// http://www.boost.org/LICENSE_1_0.txt)
7//
8// For more information, see http://www.boost.org/libs/range/
9//
10// Acknowledgments:
11// Ticket #8341: Arno Schoedl - improved handling of has_range_iterator upon
12// use-cases where T was const.
13#ifndef BOOST_RANGE_HAS_ITERATOR_HPP_INCLUDED
14#define BOOST_RANGE_HAS_ITERATOR_HPP_INCLUDED
15
16#include <boost/mpl/bool.hpp>
17#include <boost/mpl/eval_if.hpp>
18#include <boost/mpl/has_xxx.hpp>
19#include <boost/range/iterator.hpp>
20#include <boost/type_traits/remove_reference.hpp>
21#include <boost/utility/enable_if.hpp>
22
23namespace boost
24{
25 namespace range_detail
26 {
27 BOOST_MPL_HAS_XXX_TRAIT_DEF(type)
28
29 template<class T, class Enabler = void>
30 struct has_range_iterator_impl
31 : boost::mpl::false_
32 {
33 };
34
35 template<class T>
36 struct has_range_iterator_impl<
37 T,
38 BOOST_DEDUCED_TYPENAME ::boost::enable_if<
39 BOOST_DEDUCED_TYPENAME mpl::eval_if<is_const<T>,
40 has_type<range_const_iterator<
41 BOOST_DEDUCED_TYPENAME remove_const<T>::type> >,
42 has_type<range_mutable_iterator<T> >
43 >::type
44 >::type
45 >
46 : boost::mpl::true_
47 {
48 };
49
50 template<class T, class Enabler = void>
51 struct has_range_const_iterator_impl
52 : boost::mpl::false_
53 {
54 };
55
56 template<class T>
57 struct has_range_const_iterator_impl<
58 T,
59 BOOST_DEDUCED_TYPENAME ::boost::enable_if<
60 has_type<range_const_iterator<T> >
61 >::type
62 >
63 : boost::mpl::true_
64 {
65 };
66
67 } // namespace range_detail
68
69 template<class T>
70 struct has_range_iterator
71 : range_detail::has_range_iterator_impl<
72 BOOST_DEDUCED_TYPENAME remove_reference<T>::type>
73 {};
74
75 template<class T>
76 struct has_range_const_iterator
77 : range_detail::has_range_const_iterator_impl<
78 BOOST_DEDUCED_TYPENAME remove_reference<T>::type>
79 {};
80} // namespace boost
81
82#endif // include guard
83
84