Add const_container

Builds/VisualStudio2013/beast.vcxproj

@@ -127,6 +127,7 @@
     <ClInclude Include="..\..\beast\container\aged_unordered_multimap.h" />
     <ClInclude Include="..\..\beast\container\aged_unordered_multiset.h" />
     <ClInclude Include="..\..\beast\container\aged_unordered_set.h" />
+    <ClInclude Include="..\..\beast\container\const_container.h" />
     <ClInclude Include="..\..\beast\container\cyclic_iterator.h" />
     <ClInclude Include="..\..\beast\container\detail\aged_associative_container.h" />
     <ClInclude Include="..\..\beast\container\detail\aged_ordered_container.h" />

Builds/VisualStudio2013/beast.vcxproj.filters

@@ -1161,6 +1161,9 @@
     <ClInclude Include="..\..\beast\utility\noexcept.h">
       <Filter>beast\utility</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\beast\container\const_container.h">
+      <Filter>beast\container</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\modules\beast_core\files\DirectoryIterator.cpp">

beast/container/const_container.h

@@ -0,0 +1,99 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_CONTAINER_CONST_CONTAINER_H_INCLUDED
+#define BEAST_CONTAINER_CONST_CONTAINER_H_INCLUDED
+
+namespace beast {
+
+/** Adapter to constrain a container interface.
+    The interface allows for limited read only operations. Derived classes
+    provide additional behavior.
+*/
+template <class Container>
+class const_container
+{
+private:
+    typedef Container cont_type;
+
+    cont_type m_cont;
+
+protected:
+    cont_type& cont()
+    {
+        return m_cont;
+    }
+
+    cont_type const& cont() const
+    {
+        return m_cont;
+    }
+
+public:
+    typedef typename cont_type::value_type value_type;
+    typedef typename cont_type::size_type size_type;
+    typedef typename cont_type::difference_type difference_type;
+    typedef typename cont_type::const_iterator iterator;
+    typedef typename cont_type::const_iterator const_iterator;
+
+    /** Returns `true` if the container is empty. */
+    bool
+    empty() const
+    {
+        return m_cont.empty();
+    }
+
+    /** Returns the number of items in the container. */
+    size_type
+    size() const
+    {
+        return m_cont.size();
+    }
+
+    /** Returns forward iterators for traversal. */
+    /** @{ */
+    const_iterator
+    begin() const
+    {
+        return m_cont.cbegin();
+    }
+
+    const_iterator
+    cbegin() const
+    {
+        return m_cont.cbegin();
+    }
+
+    const_iterator
+    end() const
+    {
+        return m_cont.cend();
+    }
+
+    const_iterator
+    cend() const
+    {
+        return m_cont.cend();
+    }
+    /** @} */
+};
+
+} // beast
+
+#endif