1 /*============================================================================= 2 Copyright (c) 2001-2006 Joel de Guzman 3 Copyright (c) 2005-2006 Dan Marsden 4 5 Distributed under the Boost Software License, Version 1.0. (See accompanying 6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 7 ==============================================================================*/ 8 #if !defined(BOOST_FUSION_ARRAY_ITERATOR_26122005_2250) 9 #define BOOST_FUSION_ARRAY_ITERATOR_26122005_2250 10 11 #include <cstddef> 12 #include <boost/config.hpp> 13 #include <boost/mpl/int.hpp> 14 #include <boost/mpl/assert.hpp> 15 #include <boost/mpl/if.hpp> 16 #include <boost/mpl/minus.hpp> 17 #include <boost/type_traits/is_const.hpp> 18 #include <boost/fusion/iterator/iterator_facade.hpp> 19 20 namespace boost { namespace fusion 21 { 22 struct random_access_traversal_tag; 23 24 template <typename Array, int Pos> 25 struct array_iterator 26 : iterator_facade<array_iterator<Array, Pos>, random_access_traversal_tag> 27 { 28 BOOST_MPL_ASSERT_RELATION(Pos, >=, 0); 29 BOOST_MPL_ASSERT_RELATION(Pos, <=, static_cast<int>(Array::static_size)); 30 31 typedef mpl::int_<Pos> index; 32 typedef Array array_type; 33 array_iteratorboost::fusion::array_iterator34 array_iterator(Array& a) 35 : array(a) {} 36 37 Array& array; 38 39 template <typename Iterator> 40 struct value_of 41 { 42 typedef typename Iterator::array_type array_type; 43 typedef typename array_type::value_type type; 44 }; 45 46 template <typename Iterator> 47 struct deref 48 { 49 typedef typename Iterator::array_type array_type; 50 typedef typename 51 mpl::if_< 52 is_const<array_type> 53 , typename array_type::const_reference 54 , typename array_type::reference 55 >::type 56 type; 57 58 static type callboost::fusion::array_iterator::deref59 call(Iterator const & it) 60 { 61 return it.array[Iterator::index::value]; 62 } 63 }; 64 65 template <typename Iterator, typename N> 66 struct advance 67 { 68 typedef typename Iterator::index index; 69 typedef typename Iterator::array_type array_type; 70 typedef array_iterator<array_type, index::value + N::value> type; 71 72 static type callboost::fusion::array_iterator::advance73 call(Iterator const& i) 74 { 75 return type(i.array); 76 } 77 }; 78 79 template <typename Iterator> 80 struct next : advance<Iterator, mpl::int_<1> > {}; 81 82 template <typename Iterator> 83 struct prior : advance<Iterator, mpl::int_<-1> > {}; 84 85 template <typename I1, typename I2> 86 struct distance : mpl::minus<typename I2::index, typename I1::index> 87 { 88 typedef typename 89 mpl::minus< 90 typename I2::index, typename I1::index 91 >::type 92 type; 93 94 static type callboost::fusion::array_iterator::distance95 call(I1 const&, I2 const&) 96 { 97 return type(); 98 } 99 }; 100 101 private: 102 103 array_iterator<Array, Pos>& operator=(array_iterator<Array, Pos> const&); 104 }; 105 }} 106 107 #endif 108