X-Git-Url: http://g0dil.de/git?a=blobdiff_plain;f=senf%2Fboost_intrusive%2Fdetail%2Febo_holder.hpp;fp=senf%2Fboost_intrusive%2Fdetail%2Febo_holder.hpp;h=29e77256829240fca14b5557464e5c39eed42b8a;hb=8f1ff66f5b7d10cfc6d35fb72267bc2fb3b588f7;hp=0000000000000000000000000000000000000000;hpb=fbd3d0ff298683f08b59f25288d8c243e03b206c;p=senf.git

diff --git a/senf/boost_intrusive/detail/ebo_holder.hpp b/senf/boost_intrusive/detail/ebo_holder.hpp
new file mode 100644
index 0000000..29e7725
--- /dev/null
+++ b/senf/boost_intrusive/detail/ebo_holder.hpp
@@ -0,0 +1,95 @@
+/////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Joaquín M López Muñoz  2006-2007
+//
+// Distributed under 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)
+//
+// See http://www.boost.org/libs/intrusive for documentation.
+//
+/////////////////////////////////////////////////////////////////////////////
+#include <boost/type_traits/is_empty.hpp>
+
+namespace boost {
+namespace intrusive {
+namespace detail {
+
+template<typename T, bool IsEmpty = false>
+class ebo_holder_impl
+{
+   public:
+   ebo_holder_impl(){}
+   ebo_holder_impl(const T& t):t(t){}
+
+   T&       get(){return t;}
+   const T& get()const{return t;}
+
+   private:
+   T t;
+};
+
+template<typename T>
+class ebo_holder_impl<T, true>
+   :  private T
+{
+   public:
+   ebo_holder_impl(){}
+   ebo_holder_impl(const T& t):T(t){}
+
+   T&       get(){return *this;}
+   const T& get()const{return *this;}
+};
+
+template<typename T>
+class ebo_holder
+   :  public ebo_holder_impl<T,boost::is_empty<T>::value>
+{
+   private:
+   typedef ebo_holder_impl<T,boost::is_empty<T>::value> super;
+
+   public:
+   ebo_holder(){}
+   ebo_holder(const T& t):super(t){}
+
+   ebo_holder& operator=(const ebo_holder& x)
+   {
+      this->get()=x.get();
+      return *this;
+   }
+};
+
+
+}  //namespace detail {
+}  //namespace intrusive {
+}  //namespace boost {
+
+/*
+
+// testing
+
+#include <boost/assert.hpp>
+#include <string>
+
+struct empty_member{};
+
+struct foo:public ebo_holder<empty_member>
+{
+  int x;
+};
+
+int main()
+{
+  ebo_holder<int> ei=5;
+  BOOST_ASSERT(ei.get()==5);
+  ei=6;
+  BOOST_ASSERT(ei.get()==6);
+
+  ebo_holder<std::string> es("hello");
+  BOOST_ASSERT(es.get()=="hello");
+  es=std::string("bye");
+  BOOST_ASSERT(es.get()=="bye");
+
+  BOOST_ASSERT(sizeof(foo)==sizeof(int)); // if EBO applies
+}
+*/