Some progress on indirect_iterator

[SVN r21710]

doc/indirect_reference_ref.rst

@@ -0,0 +1,29 @@
+.. 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 indirect_reference
+  {
+      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
+  ``pointee<Dereferenceable>::type&`` shall be well-formed.
+  Otherwise ``iterator_traits<Dereferenceable>::reference`` shall
+  be well formed.  [Note: These requirements need not apply to
+  explicit or partial specializations of ``indirect_reference``]
+
+``type`` is determined according to the following algorithm, where
+``x`` is an object of type ``Dereferenceable``::
+
+  if ( ++x is ill-formed )
+      return ``pointee<Dereferenceable>::type&``
+  else
+      std::iterator_traits<Dereferenceable>::value_type
+
+