Initial implementation and docs for path::reverse_iterator.

doc/reference.html

@@ -1102,9 +1102,13 @@ <h2 dir="ltr"><a name="class-path">Class <code>path</code> [class.path]</a></h2>
         // <a href="#path-iterators">iterators</a>
         class iterator;
         typedef iterator const_iterator;
+        class reverse_iterator;
+        typedef reverse_iterator const_reverse_iterator;
 
         iterator begin() const;
         iterator end() const;
+        reverse_iterator rbegin() const;
+        reverse_iterator rend() const;
 
         // <a href="#path-imbued-locale">imbued locale</a>
         static std::locale <a href="#path-imbue">imbue</a>(const std::locale&amp; loc);
@@ -1671,10 +1675,19 @@ <h3 dir="ltr"> <a name="path-query"> <code><font size="4">path</font></code> que
 </blockquote>
 <h3 dir="ltr"> <a name="path-iterators"> <code>
 <font size="4">path</font></code> iterators</a> [path.itr]</h3>
-<p dir="ltr"> Path iterators iterate over the elements of the stored pathname.</p>
-<p dir="ltr"> A <code>path::iterator</code> is a constant iterator satisfying all 
+<p dir="ltr"> Path iterators <code>iterator</code>, <code>const_iterator</code>,
+<code>reverse_iterator</code>, and <code>const_reverse_iterator</code> iterate over the elements of the stored pathname.</p>
+<p dir="ltr"> Path iterators are constant iterators satisfying  
 the requirements of a bidirectional iterator (C++ Std, 24.1.4 Bidirectional 
-iterators [lib.bidirectional.iterators]). Its <code>value_type</code> is <code>path</code>.</p>
+iterators [lib.bidirectional.iterators]). The <code>value_type</code>&nbsp; of 
+an iterator is <code>path</code>.</p>
+  <blockquote>
+<p dir="ltr"> [<i>Note:</i> Path iterators store their value objects internally 
+and when dereferenced return references to those internal objects. They cannot 
+be used with iterator adaptors such as <code>std::reverse_iterator</code> that 
+assume references obtained by dereferencing an iterator point to objects that 
+out-live the iterator itself. <i>—end note</i>] </p>
+</blockquote>
   <p dir="ltr">Calling any non-const member function of a <code>path</code> object 
   invalidates all iterators referring to elements of that object.</p>
 <p dir="ltr"> The forward traversal order is as follows:</p>
@@ -1697,10 +1710,19 @@ <h3 dir="ltr"> <a name="path-iterators"> <code>
   <p>The backward traversal order is the reverse of forward traversal.</p>
   <pre>iterator begin() const;</pre>
 <blockquote>
-  <p><i>Returns:</i> An iterator for the first present element in the traversal 
-  list above. If no elements are present, the end iterator.</p>
+  <p><i>Returns:</i> An iterator for the first  element in forward traversal 
+  order. If no elements are present, the end iterator.</p>
 </blockquote>
 <pre>iterator end() const;</pre>
+<blockquote>
+  <p><i>Returns:</i> The end iterator.</p>
+</blockquote>
+  <pre>reverse_iterator rbegin() const;</pre>
+<blockquote>
+  <p><i>Returns:</i> An iterator for the first element in backward traversal 
+  order. If no elements are present, the end iterator.</p>
+</blockquote>
+<pre>reverse_iterator rend() const;</pre>
 <blockquote>
   <p><i>Returns:</i> The end iterator.</p>
 </blockquote>
@@ -3987,7 +4009,7 @@ <h2><a name="References">References</a></h2>
 </font>
 <a href="http://www.boost.org/LICENSE_1_0.txt"><font size="2">www.boost.org/LICENSE_1_0.txt</font></a></p>
 <p><font size="2">Revised
-<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B %Y" startspan -->03 September 2015<!--webbot bot="Timestamp" endspan i-checksum="39624" --></font></p>
+<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B %Y" startspan -->04 September 2015<!--webbot bot="Timestamp" endspan i-checksum="39626" --></font></p>
 
 
 </body></html>

include/boost/filesystem/path.hpp

@@ -505,9 +505,13 @@ namespace filesystem
 
     class iterator;
     typedef iterator const_iterator;
+    class reverse_iterator;
+    typedef reverse_iterator const_reverse_iterator;
 
     iterator begin() const;
     iterator end() const;
+    reverse_iterator rbegin() const;
+    reverse_iterator rend() const;
 
     //  -----  static member functions  -----
 
@@ -624,6 +628,7 @@ namespace filesystem
   private:
     friend class boost::iterator_core_access;
     friend class boost::filesystem::path;
+    friend class boost::filesystem::path::reverse_iterator;
     friend void m_path_iterator_increment(path::iterator & it);
     friend void m_path_iterator_decrement(path::iterator & it);
 
@@ -649,6 +654,53 @@ namespace filesystem
                                          // m_pos == m_path_ptr->m_pathname.size()
   }; // path::iterator
 
+  //------------------------------------------------------------------------------------//
+  //                             class path::reverse_iterator                                   //
+  //------------------------------------------------------------------------------------//
+
+  class path::reverse_iterator
+    : public boost::iterator_facade<
+      path::reverse_iterator,
+      path const,
+      boost::bidirectional_traversal_tag >
+  {
+  public:
+
+    explicit reverse_iterator(iterator itr) : m_itr(itr)
+    {
+      if (itr != itr.m_path_ptr->begin())
+        m_element = *--itr;
+    }
+  private:
+    friend class boost::iterator_core_access;
+    friend class boost::filesystem::path;
+
+    const path& dereference() const { return m_element; }
+    bool equal(const reverse_iterator& rhs) const { return m_itr == rhs.m_itr; }
+    void increment()
+    { 
+      --m_itr;
+      if (m_itr != m_itr.m_path_ptr->begin())
+      {
+        iterator tmp = m_itr;
+        m_element = *--tmp;
+      }
+    }
+    void decrement()
+    {
+      m_element = *m_itr;
+      ++m_itr;
+    }
+
+    iterator m_itr;
+    path     m_element;
+
+  }; // path::reverse_iterator
+
+  inline path::reverse_iterator path::rbegin() const { return reverse_iterator(end()); }
+  inline path::reverse_iterator path::rend() const   { return reverse_iterator(begin()); }
+
+
   //------------------------------------------------------------------------------------//
   //                                                                                    //
   //                              non-member functions                                  //

test/msvc/issue_test/issue_test.vcxproj

@@ -95,7 +95,7 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="..\..\issues\11166-remove-race.cpp" />
+    <ClCompile Include="..\..\issues\11061-imposible-to-traverse-path-reverse-iterator.cpp" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">