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 28 namespace boost{ 29 namespace detail{ 30 31 template <class I> 32 struct is_random_imp 33 { 34 #ifndef BOOST_NO_STD_ITERATOR_TRAITS 35 private: 36 typedef typename std::iterator_traits<I>::iterator_category cat; 37 public: 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 44 template <class I> 45 struct is_random_pointer_imp 46 { 47 BOOST_STATIC_CONSTANT(bool, value = true); 48 }; 49 50 template <bool is_pointer_type> 51 struct is_random_imp_selector 52 { 53 template <class I> 54 struct rebind 55 { 56 typedef is_random_imp<I> type; 57 }; 58 }; 59 60 template <> 61 struct 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 72 template <class I> 73 struct is_random_access_iterator 74 { 75 private: 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; 79 public: 80 BOOST_STATIC_CONSTANT(bool, value = answer::value); 81 }; 82 83 #ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION 84 template <class I> 85 const bool is_random_access_iterator<I>::value; 86 #endif 87 88 } 89 90 #endif 91 92