Add ScopedWrapperContext

Builds/VisualStudio2012/beast.vcxproj

@@ -172,6 +172,7 @@
     <ClInclude Include="..\..\beast\threads\TryLockGuard.h" />
     <ClInclude Include="..\..\beast\threads\UnlockGuard.h" />
     <ClInclude Include="..\..\beast\threads\WaitableEvent.h" />
+    <ClInclude Include="..\..\beast\threads\ScopedWrapperContext.h" />
     <ClInclude Include="..\..\beast\TypeTraits.h" />
     <ClInclude Include="..\..\beast\type_traits\IntegralConstant.h" />
     <ClInclude Include="..\..\beast\type_traits\IsIntegral.h" />

Builds/VisualStudio2012/beast.vcxproj.filters

@@ -1248,6 +1248,9 @@
     <ClInclude Include="..\..\beast\utility\PropertyStream.h">
       <Filter>beast\utility</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\beast\threads\ScopedWrapperContext.h">
+      <Filter>beast\threads</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\modules\beast_core\containers\AbstractFifo.cpp">

beast/Threads.h

@@ -32,5 +32,6 @@
 #include "threads/Thread.h"
 #include "threads/ThreadLocalValue.h"
 #include "threads/WaitableEvent.h"
+#include "threads/ScopedWrapperContext.h"
 
 #endif

beast/threads/ScopedWrapperContext.h

@@ -0,0 +1,93 @@
+//------------------------------------------------------------------------------
+/*
+    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_THREADS_WRAPSCOPED_H_INCLUDED
+#define BEAST_THREADS_WRAPSCOPED_H_INCLUDED
+
+namespace beast {
+
+/** Wraps a function object so invocation happens during a scoped container lifetime. */
+/** @{ */
+namespace detail {
+
+template <typename ScopedType, typename Context, typename Handler>
+class ScopedWrapper
+{
+public:
+    ScopedWrapper (Context const& context, Handler const& handler)
+        : m_context (context)
+        , m_handler (handler)
+        { }
+
+    void operator() ()
+    {
+        ScopedType const scope (m_context);
+        m_handler();
+    }
+
+private:
+    Context const& m_context;
+    Handler m_handler;
+};
+
+}
+
+//------------------------------------------------------------------------------
+
+/** Helper to eliminate the template argument at call sites. */
+template <typename Context, typename ScopedType>
+class ScopedWrapperContext
+{
+public:
+    typedef Context             context_type;
+    typedef ScopedType          scoped_type;
+
+    class Scope
+    {
+    public:
+        explicit Scope (ScopedWrapperContext const& owner)
+            : m_scope (owner.m_context)
+            { }
+    private:
+        scoped_type m_scope;
+    };
+
+    ScopedWrapperContext ()
+        { }
+
+    template <typename Arg>
+    explicit ScopedWrapperContext (Arg& arg)
+        : m_context (arg)
+        { }
+
+    template <typename Handler>
+    detail::ScopedWrapper <ScopedType, Context, Handler> wrap (
+        Handler const& handler)
+    {
+        return detail::ScopedWrapper <ScopedType, Context, Handler> (
+            m_context, handler);
+    }
+
+private:
+    Context m_context;
+};
+
+}
+
+#endif