1/*
2 *
3 * Copyright (c) 2002
4 * John Maddock
5 *
6 * Use, modification and distribution are subject to the
7 * Boost Software License, Version 1.0. (See accompanying file
8 * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9 *
10 */
11
12 /*
13 * LOCATION: see http://www.boost.org for most recent version.
14 * FILE regex_match.hpp
15 * VERSION see <boost/version.hpp>
16 * DESCRIPTION: Iterator traits for selecting an iterator type as
17 * an integral constant expression.
18 */
19
20
21#ifndef BOOST_REGEX_ITERATOR_CATEGORY_HPP
22#define BOOST_REGEX_ITERATOR_CATEGORY_HPP
23
24#include <iterator>
25#include <boost/type_traits/is_convertible.hpp>
26#include <boost/type_traits/is_pointer.hpp>
27
28namespace boost{
29namespace detail{
30
31template <class I>
32struct is_random_imp
33{
34#ifndef BOOST_NO_STD_ITERATOR_TRAITS
35private:
36 typedef typename std::iterator_traits<I>::iterator_category cat;
37public:
38 BOOST_STATIC_CONSTANT(bool, value = (::boost::is_convertible<cat*, std::random_access_iterator_tag*>::value));
39#else
40 BOOST_STATIC_CONSTANT(bool, value = false);
41#endif
42};
43
44template <class I>
45struct is_random_pointer_imp
46{
47 BOOST_STATIC_CONSTANT(bool, value = true);
48};
49
50template <bool is_pointer_type>
51struct is_random_imp_selector
52{
53 template <class I>
54 struct rebind
55 {
56 typedef is_random_imp<I> type;
57 };
58};
59
60template <>
61struct is_random_imp_selector<true>
62{
63 template <class I>
64 struct rebind
65 {
66 typedef is_random_pointer_imp<I> type;
67 };
68};
69
70}
71
72template <class I>
73struct is_random_access_iterator
74{
75private:
76 typedef detail::is_random_imp_selector< ::boost::is_pointer<I>::value> selector;
77 typedef typename selector::template rebind<I> bound_type;
78 typedef typename bound_type::type answer;
79public:
80 BOOST_STATIC_CONSTANT(bool, value = answer::value);
81};
82
83#ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
84template <class I>
85const bool is_random_access_iterator<I>::value;
86#endif
87
88}
89
90#endif
91
92