// (C) Copyright Jeremy Siek 2002. // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_ITERATOR_CONCEPTS_HPP #define BOOST_ITERATOR_CONCEPTS_HPP #include <boost/concept_check.hpp> #include <boost/iterator/iterator_categories.hpp> // Use boost::detail::iterator_traits to work around some MSVC/Dinkumware problems. #include <boost/detail/iterator.hpp> #include <boost/type_traits/is_same.hpp> #include <boost/type_traits/is_integral.hpp> #include <boost/mpl/bool.hpp> #include <boost/mpl/if.hpp> #include <boost/mpl/and.hpp> #include <boost/mpl/or.hpp> #include <boost/static_assert.hpp> // Use boost/limits to work around missing limits headers on some compilers #include <boost/limits.hpp> #include <boost/config.hpp> #include <algorithm> #include <boost/concept/detail/concept_def.hpp> namespace boost_concepts { // Used a different namespace here (instead of "boost") so that the // concept descriptions do not take for granted the names in // namespace boost. //=========================================================================== // Iterator Access Concepts BOOST_concept(ReadableIterator,(Iterator)) : boost::Assignable<Iterator> , boost::CopyConstructible<Iterator> { typedef BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<Iterator>::value_type value_type; typedef BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<Iterator>::reference reference; BOOST_CONCEPT_USAGE(ReadableIterator) { value_type v = *i; boost::ignore_unused_variable_warning(v); } private: Iterator i; }; template < typename Iterator , typename ValueType = BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<Iterator>::value_type > struct WritableIterator : boost::CopyConstructible<Iterator> { BOOST_CONCEPT_USAGE(WritableIterator) { *i = v; } private: ValueType v; Iterator i; }; template < typename Iterator , typename ValueType = BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<Iterator>::value_type > struct WritableIteratorConcept : WritableIterator<Iterator,ValueType> {}; BOOST_concept(SwappableIterator,(Iterator)) { BOOST_CONCEPT_USAGE(SwappableIterator) { std::iter_swap(i1, i2); } private: Iterator i1; Iterator i2; }; BOOST_concept(LvalueIterator,(Iterator)) { typedef typename boost::detail::iterator_traits<Iterator>::value_type value_type; BOOST_CONCEPT_USAGE(LvalueIterator) { value_type& r = const_cast<value_type&>(*i); boost::ignore_unused_variable_warning(r); } private: Iterator i; }; //=========================================================================== // Iterator Traversal Concepts BOOST_concept(IncrementableIterator,(Iterator)) : boost::Assignable<Iterator> , boost::CopyConstructible<Iterator> { typedef typename boost::iterator_traversal<Iterator>::type traversal_category; BOOST_CONCEPT_ASSERT(( boost::Convertible< traversal_category , boost::incrementable_traversal_tag >)); BOOST_CONCEPT_USAGE(IncrementableIterator) { ++i; (void)i++; } private: Iterator i; }; BOOST_concept(SinglePassIterator,(Iterator)) : IncrementableIterator<Iterator> , boost::EqualityComparable<Iterator> { BOOST_CONCEPT_ASSERT(( boost::Convertible< BOOST_DEDUCED_TYPENAME SinglePassIterator::traversal_category , boost::single_pass_traversal_tag > )); }; BOOST_concept(ForwardTraversal,(Iterator)) : SinglePassIterator<Iterator> , boost::DefaultConstructible<Iterator> { typedef typename boost::detail::iterator_traits<Iterator>::difference_type difference_type; BOOST_MPL_ASSERT((boost::is_integral<difference_type>)); BOOST_MPL_ASSERT_RELATION(std::numeric_limits<difference_type>::is_signed, ==, true); BOOST_CONCEPT_ASSERT(( boost::Convertible< BOOST_DEDUCED_TYPENAME ForwardTraversal::traversal_category , boost::forward_traversal_tag > )); }; BOOST_concept(BidirectionalTraversal,(Iterator)) : ForwardTraversal<Iterator> { BOOST_CONCEPT_ASSERT(( boost::Convertible< BOOST_DEDUCED_TYPENAME BidirectionalTraversal::traversal_category , boost::bidirectional_traversal_tag > )); BOOST_CONCEPT_USAGE(BidirectionalTraversal) { --i; (void)i--; } private: Iterator i; }; BOOST_concept(RandomAccessTraversal,(Iterator)) : BidirectionalTraversal<Iterator> { BOOST_CONCEPT_ASSERT(( boost::Convertible< BOOST_DEDUCED_TYPENAME RandomAccessTraversal::traversal_category , boost::random_access_traversal_tag > )); BOOST_CONCEPT_USAGE(RandomAccessTraversal) { i += n; i = i + n; i = n + i; i -= n; i = i - n; n = i - j; } private: typename BidirectionalTraversal<Iterator>::difference_type n; Iterator i, j; }; //=========================================================================== // Iterator Interoperability namespace detail { template <typename Iterator1, typename Iterator2> void interop_single_pass_constraints(Iterator1 const& i1, Iterator2 const& i2) { bool b; b = i1 == i2; b = i1 != i2; b = i2 == i1; b = i2 != i1; boost::ignore_unused_variable_warning(b); } template <typename Iterator1, typename Iterator2> void interop_rand_access_constraints( Iterator1 const& i1, Iterator2 const& i2, boost::random_access_traversal_tag, boost::random_access_traversal_tag) { bool b; typename boost::detail::iterator_traits<Iterator2>::difference_type n; b = i1 < i2; b = i1 <= i2; b = i1 > i2; b = i1 >= i2; n = i1 - i2; b = i2 < i1; b = i2 <= i1; b = i2 > i1; b = i2 >= i1; n = i2 - i1; boost::ignore_unused_variable_warning(b); boost::ignore_unused_variable_warning(n); } template <typename Iterator1, typename Iterator2> void interop_rand_access_constraints( Iterator1 const&, Iterator2 const&, boost::single_pass_traversal_tag, boost::single_pass_traversal_tag) { } } // namespace detail BOOST_concept(InteroperableIterator,(Iterator)(ConstIterator)) { private: typedef typename boost::detail::pure_traversal_tag< typename boost::iterator_traversal< Iterator >::type >::type traversal_category; typedef typename boost::detail::pure_traversal_tag< typename boost::iterator_traversal< ConstIterator >::type >::type const_traversal_category; public: BOOST_CONCEPT_ASSERT((SinglePassIterator<Iterator>)); BOOST_CONCEPT_ASSERT((SinglePassIterator<ConstIterator>)); BOOST_CONCEPT_USAGE(InteroperableIterator) { detail::interop_single_pass_constraints(i, ci); detail::interop_rand_access_constraints(i, ci, traversal_category(), const_traversal_category()); ci = i; } private: Iterator i; ConstIterator ci; }; } // namespace boost_concepts #include <boost/concept/detail/concept_undef.hpp> #endif // BOOST_ITERATOR_CONCEPTS_HPP