[Boost-commit] svn:boost r49263 - trunk/boost/serialization

Subject: [Boost-commit] svn:boost r49263 - trunk/boost/serialization
From: ramey_at_[hidden]
Date: 2008-10-11 01:33:00

Author: ramey
Date: 2008-10-11 01:32:59 EDT (Sat, 11 Oct 2008)
New Revision: 49263
URL: http://svn.boost.org/trac/boost/changeset/49263

Log:
Fix to make is_destoryed function as advertised
Text files modified: 
   trunk/boost/serialization/singleton.hpp |    32 +++++++++++++++++++++-----------        
   1 files changed, 21 insertions(+), 11 deletions(-)

Modified: trunk/boost/serialization/singleton.hpp
==============================================================================
--- trunk/boost/serialization/singleton.hpp	(original)
+++ trunk/boost/serialization/singleton.hpp	2008-10-11 01:32:59 EDT (Sat, 11 Oct 2008)
@@ -93,21 +93,37 @@
     }
 };
 
+namespace detail {
+
+template<class T>
+class singleton_wrapper : public T
+{
+public:
+    static bool m_is_destroyed;
+    ~singleton_wrapper(){
+        m_is_destroyed = true;
+    }
+};
+
+template<class T>
+bool detail::singleton_wrapper<T>::m_is_destroyed = false;
+
+} // detail
+
 template <class T>
 class singleton : public singleton_module
 {
 private:
-    static bool m_is_destroyed;
     BOOST_DLLEXPORT static T & instance;
     // include this to provoke instantiation at pre-execution time
     static void use(T const &) {}
     BOOST_DLLEXPORT static T & get_instance() {
-        static T t;
+        static detail::singleton_wrapper<T> t;
         // refer to instance, causing it to be instantiated (and
         // initialized at startup on working compilers)
-        assert(! m_is_destroyed);
+        assert(! detail::singleton_wrapper<T>::m_is_destroyed);
         use(instance);
-        return t;
+        return static_cast<T &>(t);
     }
 public:
     BOOST_DLLEXPORT static T & get_mutable_instance(){
@@ -118,19 +134,13 @@
         return get_instance();
     }
     BOOST_DLLEXPORT static bool is_destroyed(){
-        return m_is_destroyed;
-    }
-    ~singleton(){
-        m_is_destroyed = true;
+        return detail::singleton_wrapper<T>::m_is_destroyed;
     }
 };
 
 template<class T>
 BOOST_DLLEXPORT T & singleton<T>::instance = singleton<T>::get_instance();
 
-template<class T>
-bool singleton<T>::m_is_destroyed = false;
-
 } // namespace serialization
 } // namespace boost