From 9365853fde3061acbdd11b74b0218b80d9ef4ce0 Mon Sep 17 00:00:00 2001
From: Frank Mori Hess <fmh6jj@gmail.com>
Date: Wed, 16 Apr 2008 00:06:29 +0000
Subject: [PATCH] Avoid needless overhead of wrapping owner's deleter in
 deleter_wrapper if shared_from_this has not been called yet, as Peter
 suggested earlier.

[SVN r44448]
---
 include/boost/enable_shared_from_this.hpp | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/include/boost/enable_shared_from_this.hpp b/include/boost/enable_shared_from_this.hpp
index 23ec297..99c68ba 100644
--- a/include/boost/enable_shared_from_this.hpp
+++ b/include/boost/enable_shared_from_this.hpp
@@ -93,17 +93,21 @@ public:
     template<typename U>
     void _internal_accept_owner(shared_ptr<U> &owner) const
     {
-        init_internal_shared_once();
-
         if( !_owned )
         {
-            detail::sp_deleter_wrapper * pd = get_deleter<detail::sp_deleter_wrapper>(_internal_shared_this);
-            BOOST_ASSERT( pd != 0 );
-            pd->set_deleter(owner);
-
-            owner.reset( _internal_shared_this, owner.get() );
-            _internal_shared_this.reset();
+            if( !_internal_shared_this )
+            {
+                T * p = dynamic_cast<T *>(const_cast<enable_shared_from_this*>(this));
+                _internal_weak_this = shared_ptr<T>(owner, p);
+            }else
+            {
+                detail::sp_deleter_wrapper * pd = get_deleter<detail::sp_deleter_wrapper>(_internal_shared_this);
+                BOOST_ASSERT( pd != 0 );
+                pd->set_deleter(owner);
 
+                owner.reset( _internal_shared_this, owner.get() );
+                _internal_shared_this.reset();
+            }
             _owned = true;
         }
     }