1 // (C) Copyright Jeremy Siek 2002.
2 // Distributed under the Boost Software License, Version 1.0. (See
3 // accompanying file LICENSE_1_0.txt or copy at
4 // http://www.boost.org/LICENSE_1_0.txt)
6 #ifndef BOOST_ITERATOR_ARCHETYPES_HPP
7 #define BOOST_ITERATOR_ARCHETYPES_HPP
9 #include <boost/iterator/iterator_categories.hpp>
10 #include <boost/operators.hpp>
11 #include <boost/static_assert.hpp>
12 #include <boost/iterator.hpp>
14 #include <boost/iterator/detail/facade_iterator_category.hpp>
16 #include <boost/type_traits/is_const.hpp>
17 #include <boost/type_traits/add_const.hpp>
18 #include <boost/type_traits/remove_const.hpp>
19 #include <boost/type_traits/remove_cv.hpp>
21 #include <boost/concept_archetype.hpp>
23 #include <boost/mpl/aux_/msvc_eti_base.hpp>
24 #include <boost/mpl/bitand.hpp>
25 #include <boost/mpl/int.hpp>
26 #include <boost/mpl/equal_to.hpp>
27 #include <boost/mpl/if.hpp>
28 #include <boost/mpl/eval_if.hpp>
29 #include <boost/mpl/and.hpp>
30 #include <boost/mpl/identity.hpp>
36 template <class Value, class AccessCategory>
37 struct access_archetype;
39 template <class Derived, class Value, class AccessCategory, class TraversalCategory>
40 struct traversal_archetype;
42 namespace iterator_archetypes
45 readable_iterator_bit = 1
46 , writable_iterator_bit = 2
47 , swappable_iterator_bit = 4
48 , lvalue_iterator_bit = 8
51 // Not quite tags, since dispatching wouldn't work.
52 typedef mpl::int_<readable_iterator_bit>::type readable_iterator_t;
53 typedef mpl::int_<writable_iterator_bit>::type writable_iterator_t;
56 (readable_iterator_bit|writable_iterator_bit)
57 >::type readable_writable_iterator_t;
60 (readable_iterator_bit|lvalue_iterator_bit)
61 >::type readable_lvalue_iterator_t;
64 (lvalue_iterator_bit|writable_iterator_bit)
65 >::type writable_lvalue_iterator_t;
67 typedef mpl::int_<swappable_iterator_bit>::type swappable_iterator_t;
68 typedef mpl::int_<lvalue_iterator_bit>::type lvalue_iterator_t;
70 template <class Derived, class Base>
73 mpl::bitand_<Derived,Base>
84 assign_proxy& operator=(T) { return *this; }
90 operator T() { return static_object<T>::get(); }
94 struct read_write_proxy
95 : read_proxy<T> // Use to inherit from assign_proxy, but that doesn't work. -JGS
97 read_write_proxy& operator=(T) { return *this; }
103 T const* operator->() const { return 0; }
106 struct no_operator_brackets {};
108 template <class ValueType>
109 struct readable_operator_brackets
111 read_proxy<ValueType> operator[](std::ptrdiff_t n) const { return read_proxy<ValueType>(); }
114 template <class ValueType>
115 struct writable_operator_brackets
117 read_write_proxy<ValueType> operator[](std::ptrdiff_t n) const { return read_write_proxy<ValueType>(); }
120 template <class Value, class AccessCategory, class TraversalCategory>
121 struct operator_brackets
122 : mpl::aux::msvc_eti_base<
123 typename mpl::eval_if<
124 is_convertible<TraversalCategory, random_access_traversal_tag>
126 iterator_archetypes::has_access<
128 , iterator_archetypes::writable_iterator_t
130 , mpl::identity<writable_operator_brackets<Value> >
132 iterator_archetypes::has_access<
134 , iterator_archetypes::readable_iterator_t
136 , readable_operator_brackets<Value>
137 , no_operator_brackets
140 , mpl::identity<no_operator_brackets>
145 template <class TraversalCategory>
146 struct traversal_archetype_impl
148 template <class Derived,class Value> struct archetype;
151 // Constructor argument for those iterators that
152 // are not default constructible
155 template <class Derived, class Value, class TraversalCategory>
156 struct traversal_archetype_
157 : mpl::aux::msvc_eti_base<
158 typename traversal_archetype_impl<TraversalCategory>::template archetype<Derived,Value>
162 traversal_archetype_impl<TraversalCategory>::template archetype<Derived,Value>
165 traversal_archetype_() {}
167 traversal_archetype_(ctor_arg arg)
173 struct traversal_archetype_impl<incrementable_traversal_tag>
175 template<class Derived, class Value>
178 explicit archetype(ctor_arg) {}
180 struct bogus { }; // This use to be void, but that causes trouble for iterator_facade. Need more research. -JGS
181 typedef bogus difference_type;
183 Derived& operator++() { return (Derived&)static_object<Derived>::get(); }
184 Derived operator++(int) const { return (Derived&)static_object<Derived>::get(); }
189 struct traversal_archetype_impl<single_pass_traversal_tag>
191 template<class Derived, class Value>
193 : public equality_comparable< traversal_archetype_<Derived, Value, single_pass_traversal_tag> >,
194 public traversal_archetype_<Derived, Value, incrementable_traversal_tag>
196 explicit archetype(ctor_arg arg)
197 : traversal_archetype_<Derived, Value, incrementable_traversal_tag>(arg)
200 typedef std::ptrdiff_t difference_type;
204 template <class Derived, class Value>
205 bool operator==(traversal_archetype_<Derived, Value, single_pass_traversal_tag> const&,
206 traversal_archetype_<Derived, Value, single_pass_traversal_tag> const&) { return true; }
208 #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
209 // doesn't seem to pick up != from equality_comparable
210 template <class Derived, class Value>
211 bool operator!=(traversal_archetype_<Derived, Value, single_pass_traversal_tag> const&,
212 traversal_archetype_<Derived, Value, single_pass_traversal_tag> const&) { return true; }
215 struct traversal_archetype_impl<forward_traversal_tag>
217 template<class Derived, class Value>
219 : public traversal_archetype_<Derived, Value, single_pass_traversal_tag>
222 : traversal_archetype_<Derived, Value, single_pass_traversal_tag>(ctor_arg())
228 struct traversal_archetype_impl<bidirectional_traversal_tag>
230 template<class Derived, class Value>
232 : public traversal_archetype_<Derived, Value, forward_traversal_tag>
234 Derived& operator--() { return static_object<Derived>::get(); }
235 Derived operator--(int) const { return static_object<Derived>::get(); }
240 struct traversal_archetype_impl<random_access_traversal_tag>
242 template<class Derived, class Value>
244 : public traversal_archetype_<Derived, Value, bidirectional_traversal_tag>
246 Derived& operator+=(std::ptrdiff_t) { return static_object<Derived>::get(); }
247 Derived& operator-=(std::ptrdiff_t) { return static_object<Derived>::get(); }
251 template <class Derived, class Value>
252 Derived& operator+(traversal_archetype_<Derived, Value, random_access_traversal_tag> const&,
253 std::ptrdiff_t) { return static_object<Derived>::get(); }
255 template <class Derived, class Value>
256 Derived& operator+(std::ptrdiff_t,
257 traversal_archetype_<Derived, Value, random_access_traversal_tag> const&)
258 { return static_object<Derived>::get(); }
260 template <class Derived, class Value>
261 Derived& operator-(traversal_archetype_<Derived, Value, random_access_traversal_tag> const&,
263 { return static_object<Derived>::get(); }
265 template <class Derived, class Value>
266 std::ptrdiff_t operator-(traversal_archetype_<Derived, Value, random_access_traversal_tag> const&,
267 traversal_archetype_<Derived, Value, random_access_traversal_tag> const&)
270 template <class Derived, class Value>
271 bool operator<(traversal_archetype_<Derived, Value, random_access_traversal_tag> const&,
272 traversal_archetype_<Derived, Value, random_access_traversal_tag> const&)
275 template <class Derived, class Value>
276 bool operator>(traversal_archetype_<Derived, Value, random_access_traversal_tag> const&,
277 traversal_archetype_<Derived, Value, random_access_traversal_tag> const&)
280 template <class Derived, class Value>
281 bool operator<=(traversal_archetype_<Derived, Value, random_access_traversal_tag> const&,
282 traversal_archetype_<Derived, Value, random_access_traversal_tag> const&)
285 template <class Derived, class Value>
286 bool operator>=(traversal_archetype_<Derived, Value, random_access_traversal_tag> const&,
287 traversal_archetype_<Derived, Value, random_access_traversal_tag> const&)
292 template <class Value>
293 struct convertible_type
294 : mpl::if_< is_const<Value>,
295 typename remove_const<Value>::type,
299 } // namespace detail
302 template <class> struct undefined;
304 template <class AccessCategory>
305 struct iterator_access_archetype_impl
307 template <class Value> struct archetype;
310 template <class Value, class AccessCategory>
311 struct iterator_access_archetype
312 : mpl::aux::msvc_eti_base<
313 typename iterator_access_archetype_impl<
315 >::template archetype<Value>
321 struct iterator_access_archetype_impl<
322 iterator_archetypes::readable_iterator_t
325 template <class Value>
328 typedef typename remove_cv<Value>::type value_type;
329 typedef Value reference;
330 typedef Value* pointer;
332 value_type operator*() const { return static_object<value_type>::get(); }
334 detail::arrow_proxy<Value> operator->() const { return detail::arrow_proxy<Value>(); }
339 struct iterator_access_archetype_impl<
340 iterator_archetypes::writable_iterator_t
343 template <class Value>
346 # if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
347 BOOST_STATIC_ASSERT(!is_const<Value>::value);
349 typedef void value_type;
350 typedef void reference;
351 typedef void pointer;
353 detail::assign_proxy<Value> operator*() const { return detail::assign_proxy<Value>(); }
358 struct iterator_access_archetype_impl<
359 iterator_archetypes::readable_writable_iterator_t
362 template <class Value>
364 : public virtual iterator_access_archetype<
365 Value, iterator_archetypes::readable_iterator_t
368 typedef detail::read_write_proxy<Value> reference;
370 detail::read_write_proxy<Value> operator*() const { return detail::read_write_proxy<Value>(); }
375 struct iterator_access_archetype_impl<iterator_archetypes::readable_lvalue_iterator_t>
377 template <class Value>
379 : public virtual iterator_access_archetype<
380 Value, iterator_archetypes::readable_iterator_t
383 typedef Value& reference;
385 Value& operator*() const { return static_object<Value>::get(); }
386 Value* operator->() const { return 0; }
391 struct iterator_access_archetype_impl<iterator_archetypes::writable_lvalue_iterator_t>
393 template <class Value>
395 : public virtual iterator_access_archetype<
396 Value, iterator_archetypes::readable_lvalue_iterator_t
399 # if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
400 BOOST_STATIC_ASSERT((!is_const<Value>::value));
406 template <class Value, class AccessCategory, class TraversalCategory>
407 struct iterator_archetype;
409 template <class Value, class AccessCategory, class TraversalCategory>
410 struct traversal_archetype_base
411 : detail::operator_brackets<
412 typename remove_cv<Value>::type
416 , detail::traversal_archetype_<
417 iterator_archetype<Value, AccessCategory, TraversalCategory>
426 template <class Value, class AccessCategory, class TraversalCategory>
427 struct iterator_archetype_base
428 : iterator_access_archetype<Value, AccessCategory>
429 , traversal_archetype_base<Value, AccessCategory, TraversalCategory>
431 typedef iterator_access_archetype<Value, AccessCategory> access;
433 typedef typename detail::facade_iterator_category<
435 , typename mpl::eval_if<
436 iterator_archetypes::has_access<
437 AccessCategory, iterator_archetypes::writable_iterator_t
439 , remove_const<Value>
442 , typename access::reference
443 >::type iterator_category;
445 // Needed for some broken libraries (see below)
446 typedef boost::iterator<
449 , typename traversal_archetype_base<
450 Value, AccessCategory, TraversalCategory
452 , typename access::pointer
453 , typename access::reference
454 > workaround_iterator_base;
458 template <class Value, class AccessCategory, class TraversalCategory>
459 struct iterator_archetype
460 : public detail::iterator_archetype_base<Value, AccessCategory, TraversalCategory>
462 // These broken libraries require derivation from std::iterator
463 // (or related magic) in order to handle iter_swap and other
464 // iterator operations
465 # if BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, < 310) \
466 || BOOST_WORKAROUND(_RWSTD_VER, BOOST_TESTED_AT(0x20101))
467 , public detail::iterator_archetype_base<
468 Value, AccessCategory, TraversalCategory
469 >::workaround_iterator_base
472 // Derivation from std::iterator above caused references to nested
473 // types to be ambiguous, so now we have to redeclare them all
475 # if BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, < 310) \
476 || BOOST_WORKAROUND(_RWSTD_VER, BOOST_TESTED_AT(0x20101))
478 typedef detail::iterator_archetype_base<
479 Value,AccessCategory,TraversalCategory
482 typedef typename base::value_type value_type;
483 typedef typename base::reference reference;
484 typedef typename base::pointer pointer;
485 typedef typename base::difference_type difference_type;
486 typedef typename base::iterator_category iterator_category;
489 iterator_archetype() { }
490 iterator_archetype(iterator_archetype const& x)
491 : detail::iterator_archetype_base<
498 iterator_archetype& operator=(iterator_archetype const&)
502 // Optional conversion from mutable
505 typename detail::convertible_type<Value>::type
507 , TraversalCategory> const&
515 #endif // BOOST_ITERATOR_ARCHETYPES_HPP