Some progress on indirect_iterator

[SVN r21710]

doc/pointee_ref.rst

@@ -0,0 +1,38 @@
+.. Copyright David Abrahams 2004. Use, modification and distribution is
+.. subject to 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)
+
+::
+
+  template <class Dereferenceable>
+  struct pointee
+  {
+      typedef /* see below */ type;
+  };
+
+:Requires: For an object ``x`` of type ``Dereferenceable``, ``*x``
+  is well-formed.  If ``++x`` is ill-formed it shall neither be
+  ambiguous nor shall it violate access control, and
+  ``Dereferenceable::element_type`` shall be an accessible type.
+  Otherwise ``iterator_traits<Dereferenceable>::value_type`` shall
+  be well formed.  [Note: These requirements need not apply to
+  explicit or partial specializations of ``pointee``]
+
+``type`` is determined according to the following algorithm, where
+``x`` is an object of type ``Dereferenceable``::
+
+  if ( ++x is ill-formed )
+  {
+      return ``Dereferenceable::element_type``
+  }
+  else if (``*x`` is a mutable reference to
+           std::iterator_traits<Dereferenceable>::value_type)
+  {
+      return iterator_traits<Dereferenceable>::value_type
+  }
+  else
+  {
+      return iterator_traits<Dereferenceable>::value_type const
+  }
+
+