Implements N3644.

- Avoid deriving from std::iterator_traits as iterators become too fat.
- Use intrusive's reverse_iterator some std::reverse_iterator-s don't value initialize base.

test/null_iterators_test.cpp

@@ -0,0 +1,97 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2014-2014. 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)
+//
+// See http://www.boost.org/libs/container for documentation.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+#include <boost/container/vector.hpp>
+#include <boost/container/deque.hpp>
+#include <boost/container/stable_vector.hpp>
+#include <boost/container/static_vector.hpp>
+#include <boost/container/string.hpp>
+#include <boost/container/list.hpp>
+#include <boost/container/slist.hpp>
+#include <boost/container/map.hpp>
+#include <boost/container/set.hpp>
+#include <boost/container/flat_set.hpp>
+#include <boost/container/flat_map.hpp>
+#include <boost/intrusive/detail/memory_util.hpp>
+
+#include <boost/core/lightweight_test.hpp>
+#include <boost/aligned_storage.hpp>
+#include <boost/static_assert.hpp>
+#include <cstring>
+#include <new>
+
+using namespace boost::container;
+
+typedef boost::aligned_storage<sizeof(void*)*4>::type buffer_t;
+
+static buffer_t buffer_0x00;
+static buffer_t buffer_0xFF;
+
+template<class Iterator>
+const Iterator &on_0x00_buffer()
+{
+   BOOST_STATIC_ASSERT(sizeof(buffer_t) >= sizeof(Iterator));
+   return * ::new(std::memset(&buffer_0x00, 0x00, sizeof(buffer_0x00))) Iterator();
+}
+
+template<class Iterator>
+const Iterator &on_0xFF_buffer()
+{
+   BOOST_STATIC_ASSERT(sizeof(buffer_t) >= sizeof(Iterator));
+   return * ::new(std::memset(&buffer_0xFF, 0xFF, sizeof(buffer_0xFF))) Iterator();
+}
+
+namespace boost {
+namespace container {
+namespace test {
+
+BOOST_INTRUSIVE_INSTANTIATE_DEFAULT_TYPE_TMPLT(reverse_iterator)
+BOOST_INTRUSIVE_INSTANTIATE_DEFAULT_TYPE_TMPLT(const_reverse_iterator)
+
+}}}   //namespace boost::container::test {
+
+template<class Container>
+void check_null_iterators()
+{
+   typedef typename Container::iterator               iterator;
+   typedef typename Container::const_iterator         const_iterator;
+   typedef BOOST_INTRUSIVE_OBTAIN_TYPE_WITH_DEFAULT
+      (boost::container::test::, Container
+      ,reverse_iterator, iterator)                    reverse_iterator;
+   typedef BOOST_INTRUSIVE_OBTAIN_TYPE_WITH_DEFAULT
+      (boost::container::test::, Container
+      ,const_reverse_iterator, const_iterator)        const_reverse_iterator;
+
+   BOOST_TEST(on_0xFF_buffer<iterator>()               == on_0x00_buffer<iterator>());
+   BOOST_TEST(on_0xFF_buffer<const_iterator>()         == on_0x00_buffer<const_iterator>());
+   BOOST_TEST(on_0xFF_buffer<reverse_iterator>()       == on_0x00_buffer<reverse_iterator>());
+   BOOST_TEST(on_0xFF_buffer<const_reverse_iterator>() == on_0x00_buffer<const_reverse_iterator>());
+}
+
+int main()
+{
+   check_null_iterators< vector<int> >();
+   check_null_iterators< deque<int> >();
+   check_null_iterators< stable_vector<int> >();
+   check_null_iterators< static_vector<int, 1> >();
+   check_null_iterators< string >();
+   check_null_iterators< list<int> >();
+   check_null_iterators< slist<int> >();
+   check_null_iterators< map<int, int> >();
+   check_null_iterators< multimap<int, int> >();
+   check_null_iterators< set<int> >();
+   check_null_iterators< multiset<int> >();
+   check_null_iterators< flat_set<int> >();
+   check_null_iterators< flat_multiset<int> >();
+   check_null_iterators< flat_map<int, int> >();
+   check_null_iterators< flat_multimap<int, int> >();
+
+   return boost::report_errors();
+}