Renamed enable_shared_from_this2 to enable_shared_from_raw and

added shared_from_raw free function.  These changes fix the pointer 
value in shared_ptr which were obtained before an external shared_ptr has
taken ownership of the object (for example when a shared_ptr to
this is obtained in an object's constructor).



[SVN r57197]

include/boost/smart_ptr/enable_shared_from_raw.hpp

@@ -0,0 +1,157 @@
+#ifndef BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED
+#define BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED
+
+//
+//  enable_shared_from_raw.hpp
+//
+//  Copyright 2002, 2009 Peter Dimov
+//  Copyright 2008-2009 Frank Mori Hess
+//
+//  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
+//
+
+#include <boost/config.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/weak_ptr.hpp>
+#include <boost/assert.hpp>
+#include <boost/detail/workaround.hpp>
+
+namespace boost
+{
+template<typename T> boost::shared_ptr<T> shared_from_raw(T *);
+
+namespace detail
+{
+template< class X, class Y > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe );
+
+class esft2_deleter_wrapper
+{
+private:
+
+    shared_ptr<void> deleter_;
+
+public:
+
+    esft2_deleter_wrapper()
+    {
+    }
+
+    template< class T > void set_deleter( shared_ptr<T> const & deleter )
+    {
+        deleter_ = deleter;
+    }
+
+    template< class T> void operator()( T* )
+    {
+        BOOST_ASSERT( deleter_.use_count() <= 1 );
+        deleter_.reset();
+    }
+};
+
+} // namespace detail
+
+class enable_shared_from_raw
+{
+protected:
+
+    enable_shared_from_raw()
+    {
+    }
+
+    enable_shared_from_raw( enable_shared_from_raw const & )
+    {
+    }
+
+    enable_shared_from_raw & operator=( enable_shared_from_raw const & )
+    {
+        return *this;
+    }
+
+    ~enable_shared_from_raw()
+    {
+        BOOST_ASSERT( shared_this_.use_count() <= 1 ); // make sure no dangling shared_ptr objects exist
+    }
+
+private:
+
+    mutable weak_ptr<void> weak_this_;
+    mutable shared_ptr<void> shared_this_;
+
+private:
+
+    void init_weak_once() const
+    {
+        if( weak_this_.expired() )
+        {
+            shared_this_.reset( static_cast<void*>(0), detail::esft2_deleter_wrapper() );
+            weak_this_ = shared_this_;
+        }
+    }
+
+#ifdef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
+public:
+#else
+private:
+    template<class Y> friend class shared_ptr;
+    template<typename T> friend boost::shared_ptr<T> shared_from_raw(T *);
+    template< class X, class Y > friend inline void detail::sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe );
+#endif
+
+    shared_ptr<void> shared_from_this()
+    {
+        init_weak_once();
+        return shared_ptr<void>( weak_this_ );
+    }
+
+    shared_ptr<const void> shared_from_this() const
+    {
+        init_weak_once();
+        return shared_ptr<const void>( weak_this_ );
+    }
+
+    // Note: invoked automatically by shared_ptr; do not call
+    template<class X, class Y> void _internal_accept_owner( shared_ptr<X> * ppx, Y * py ) const
+    {
+        BOOST_ASSERT( ppx != 0 );
+
+        if( weak_this_.expired() )
+        {
+            weak_this_ = *ppx;
+        }
+        else if( shared_this_.use_count() != 0 )
+        {
+            BOOST_ASSERT( ppx->unique() ); // no weak_ptrs should exist either, but there's no way to check that
+
+            detail::esft2_deleter_wrapper * pd = boost::get_deleter<detail::esft2_deleter_wrapper>( shared_this_ );
+            BOOST_ASSERT( pd != 0 );
+
+            pd->set_deleter( *ppx );
+
+            ppx->reset( shared_this_, ppx->get() );
+            shared_this_.reset();
+        }
+    }
+};
+
+template<typename T>
+boost::shared_ptr<T> shared_from_raw(T *p)
+{
+    return boost::shared_ptr<T>(p->enable_shared_from_raw::shared_from_this(), p);
+}
+
+namespace detail
+{
+    template< class X, class Y > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe )
+    {
+        if( pe != 0 )
+        {
+            pe->_internal_accept_owner( ppx, const_cast< Y* >( py ) );
+        }
+    }
+} // namepsace detail
+
+} // namespace boost
+
+#endif  // #ifndef BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED

include/boost/smart_ptr/enable_shared_from_this2.hpp

@@ -1,132 +0,0 @@
-#ifndef BOOST_ENABLE_SHARED_FROM_THIS2_HPP_INCLUDED
-#define BOOST_ENABLE_SHARED_FROM_THIS2_HPP_INCLUDED
-
-//
-//  enable_shared_from_this2.hpp
-//
-//  Copyright 2002, 2009 Peter Dimov
-//  Copyright 2008 Frank Mori Hess
-//
-//  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
-//
-
-#include <boost/config.hpp>
-#include <boost/shared_ptr.hpp>
-#include <boost/assert.hpp>
-#include <boost/detail/workaround.hpp>
-
-namespace boost
-{
-
-namespace detail
-{
-
-class esft2_deleter_wrapper
-{
-private:
-
-    shared_ptr<void> deleter_;
-
-public:
-
-    esft2_deleter_wrapper()
-    {
-    }
-
-    template< class T > void set_deleter( shared_ptr<T> const & deleter )
-    {
-        deleter_ = deleter;
-    }
-
-    template< class T> void operator()( T* )
-    {
-        BOOST_ASSERT( deleter_.use_count() <= 1 );
-        deleter_.reset();
-    }
-};
-
-} // namespace detail
-
-template< class T > class enable_shared_from_this2
-{
-protected:
-
-    enable_shared_from_this2()
-    {
-    }
-
-    enable_shared_from_this2( enable_shared_from_this2 const & )
-    {
-    }
-
-    enable_shared_from_this2 & operator=( enable_shared_from_this2 const & )
-    {
-        return *this;
-    }
-
-    ~enable_shared_from_this2()
-    {
-        BOOST_ASSERT( shared_this_.use_count() <= 1 ); // make sure no dangling shared_ptr objects exist
-    }
-
-private:
-
-    mutable weak_ptr<T> weak_this_;
-    mutable shared_ptr<T> shared_this_;
-
-public:
-
-    shared_ptr<T> shared_from_this()
-    {
-        init_weak_once();
-        return shared_ptr<T>( weak_this_ );
-    }
-
-    shared_ptr<T const> shared_from_this() const
-    {
-        init_weak_once();
-        return shared_ptr<T>( weak_this_ );
-    }
-
-private:
-
-    void init_weak_once() const
-    {
-        if( weak_this_._empty() )
-        {
-            shared_this_.reset( static_cast< T* >( 0 ), detail::esft2_deleter_wrapper() );
-            weak_this_ = shared_this_;
-        }
-    }
-
-public: // actually private, but avoids compiler template friendship issues
-
-    // Note: invoked automatically by shared_ptr; do not call
-    template<class X, class Y> void _internal_accept_owner( shared_ptr<X> * ppx, Y * py ) const
-    {
-        BOOST_ASSERT( ppx != 0 );
-
-        if( weak_this_.use_count() == 0 )
-        {
-            weak_this_ = shared_ptr<T>( *ppx, py );
-        }
-        else if( shared_this_.use_count() != 0 )
-        {
-            BOOST_ASSERT( ppx->unique() ); // no weak_ptrs should exist either, but there's no way to check that
-
-            detail::esft2_deleter_wrapper * pd = boost::get_deleter<detail::esft2_deleter_wrapper>( shared_this_ );
-            BOOST_ASSERT( pd != 0 );
-
-            pd->set_deleter( *ppx );
-
-            ppx->reset( shared_this_, ppx->get() );
-            shared_this_.reset();
-        }
-    }
-};
-
-} // namespace boost
-
-#endif  // #ifndef BOOST_ENABLE_SHARED_FROM_THIS2_HPP_INCLUDED

include/boost/smart_ptr/shared_ptr.hpp

@@ -61,7 +61,7 @@ namespace boost
 template<class T> class shared_ptr;
 template<class T> class weak_ptr;
 template<class T> class enable_shared_from_this;
-template<class T> class enable_shared_from_this2;
+class enable_shared_from_raw;
 
 namespace detail
 {
@@ -110,13 +110,7 @@ template< class X, class Y, class T > inline void sp_enable_shared_from_this( bo
     }
 }
 
-template< class X, class Y, class T > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_this2< T > const * pe )
+template< class X, class Y > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe );
-{
-    if( pe != 0 )
-    {
-        pe->_internal_accept_owner( ppx, const_cast< Y* >( py ) );
-    }
-}
 
 #ifdef _MANAGED
 

test/esft_constructor_test.cpp

@@ -13,14 +13,13 @@
 //  See accompanying file LICENSE_1_0.txt or copy at
 //  http://www.boost.org/LICENSE_1_0.txt)
 //
-
+#include <boost/smart_ptr/enable_shared_from_raw.hpp>
-#include <boost/smart_ptr/enable_shared_from_this2.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/weak_ptr.hpp>
 #include <boost/detail/lightweight_test.hpp>
 #include <memory>
 
-class X: public boost::enable_shared_from_this2< X >
+class X: public boost::enable_shared_from_raw
 {
 private:
 
@@ -42,7 +41,7 @@ public:
     explicit X( int expected, boost::shared_ptr<X> *early_px = 0 ): destroyed_( 0 ), deleted_( 0 ), expected_( expected )
     {
         ++instances;
-        if( early_px ) *early_px = shared_from_this();
+        if( early_px ) *early_px = shared_from_raw(this);
     }
 
     ~X()
@@ -75,7 +74,7 @@ bool are_shared_owners(const boost::shared_ptr<T> &a, const boost::shared_ptr<U>
     return !(a < b) && !(b < a);
 }
 
-struct Y: public boost::enable_shared_from_this2<Y>
+struct Y: public boost::enable_shared_from_raw
 {};
 
 int main()
@@ -87,6 +86,7 @@ int main()
         X* x = new X( 1, &early_px );
         BOOST_TEST( early_px.use_count() > 0 );
         BOOST_TEST( boost::get_deleter<X::deleter_type>(early_px) == 0 );
+        BOOST_TEST( early_px.get() == x );
         boost::shared_ptr<X> px( x, &X::deleter2 );
         BOOST_TEST( early_px.use_count() == 2 && px.use_count() == 2 );
         BOOST_TEST(are_shared_owners(early_px, px));
@@ -117,7 +117,7 @@ int main()
 
     {
         boost::shared_ptr<X> early_px;
-        X x( 1, &early_px );
+        X x( 2, &early_px );
         BOOST_TEST( early_px.use_count() > 0 );
         boost::shared_ptr<X> px( &x, &X::deleter );
         BOOST_TEST( early_px.use_count() == 2 && px.use_count() == 2 );
@@ -125,13 +125,11 @@ int main()
         BOOST_TEST( px.use_count() == 1 );
         BOOST_TEST( X::instances == 1 );
         px.reset();
-        try
+        // test reinitialization after all shared_ptr have expired
-        {
+        early_px = shared_from_raw(&x);
-            x.shared_from_this();
+        px.reset( &x, &X::deleter );
-            BOOST_ERROR("x did not throw bad_weak_ptr");
+        BOOST_TEST(are_shared_owners(early_px, px));
-        }
+        early_px.reset();
-        catch( const boost::bad_weak_ptr & )
-        {}
     }
 
     BOOST_TEST( X::instances == 0 );
@@ -157,7 +155,7 @@ int main()
         px.reset();
         try
         {
-            y.shared_from_this();
+            shared_from_raw(&y);
         }
         catch( const boost::bad_weak_ptr & )
         {