Add BaseFromMember

Builds/VisualStudio2012/beast.vcxproj

@@ -180,6 +180,7 @@
     <ClInclude Include="..\..\beast\type_traits\RemoveSigned.h" />
     <ClInclude Include="..\..\beast\Uncopyable.h" />
     <ClInclude Include="..\..\beast\Utility.h" />
+    <ClInclude Include="..\..\beast\utility\BaseFromMember.h" />
     <ClInclude Include="..\..\beast\utility\Debug.h" />
     <ClInclude Include="..\..\beast\utility\EnableIf.h" />
     <ClInclude Include="..\..\beast\utility\Error.h" />

Builds/VisualStudio2012/beast.vcxproj.filters

@@ -1251,6 +1251,9 @@
     <ClInclude Include="..\..\beast\threads\ScopedWrapperContext.h">
       <Filter>beast\threads</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\beast\utility\BaseFromMember.h">
+      <Filter>beast\utility</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\modules\beast_core\containers\AbstractFifo.cpp">

beast/Utility.h

@@ -20,6 +20,7 @@
 #ifndef BEAST_UTILITY_H_INCLUDED
 #define BEAST_UTILITY_H_INCLUDED
 
+#include "utility/BaseFromMember.h"
 #include "utility/Debug.h"
 #include "utility/EnableIf.h"
 #include "utility/Error.h"

beast/utility/BaseFromMember.h

@@ -0,0 +1,71 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012, 2013 Ripple Labs Inc.
+
+    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_UTILITY_BASEFROMMEMBER_H_INCLUDED
+#define BEAST_UTILITY_BASEFROMMEMBER_H_INCLUDED
+
+namespace beast {
+
+template <typename T, int UniqueID = 0>
+class BaseFromMember
+{
+private:
+    T m_t;
+
+public:
+    BaseFromMember ()
+        : m_t (T())
+    {
+    }
+
+    template <class P1>
+    explicit BaseFromMember (P1 const& p1)
+        : m_t (p1)
+        { }
+
+    template <class P1, class P2>
+    BaseFromMember (P1 const& p1, P2 const& p2)
+        : m_t (p1, p2)
+        { }
+
+    template <class P1, class P2, class P3>
+    BaseFromMember (P1 const& p1, P2 const& p2, P3 const& p3)
+        : m_t (p1, p2, p3)
+        { }
+
+    template <class P1, class P2, class P3, class P4>
+    BaseFromMember (P1 const& p1, P2 const& p2, P3 const& p3, P4 const& p4)
+        : m_t (p1, p2, p3, p4)
+        { }
+
+    template <class P1, class P2, class P3, class P4, class P5>
+    BaseFromMember (P1 const& p1, P2 const& p2, P3 const& p3, P4 const& p4, P5 const& p5)
+        : m_t (p1, p2, p3, p4, p5)
+        { }
+
+    T& member()
+        { return m_t; }
+
+    T const& member() const
+        { return m_t; }
+};
+
+}
+
+#endif