Enable move-only deleters

include/boost/smart_ptr/detail/shared_count.hpp

@@ -388,7 +388,7 @@ public:
         typedef typename sp_convert_reference<D>::type D2;
 
         D2 d2( static_cast<D&&>( r.get_deleter() ) );
-        pi_ = new sp_counted_impl_pd< typename std::unique_ptr<Y, D>::pointer, D2 >( r.get(), static_cast< D2&& >( d2 ) );
+        pi_ = new sp_counted_impl_pd< typename std::unique_ptr<Y, D>::pointer, D2 >( r.get(), d2 );
 
 #ifdef BOOST_NO_EXCEPTIONS
 

include/boost/smart_ptr/detail/sp_counted_impl.hpp

@@ -156,13 +156,15 @@ public:
 
     // pre: d(p) must not throw
 
-    sp_counted_impl_pd( P p, D & d ): ptr( p ), del( d )
+#if !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
+
+    sp_counted_impl_pd( P p, D & d ): ptr( p ), del( static_cast< D&& >( d ) )
     {
     }
 
-#if !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
+#else
 
-    sp_counted_impl_pd( P p, D && d ): ptr( p ), del( static_cast< D&& >( d ) )
+    sp_counted_impl_pd( P p, D & d ): ptr( p ), del( d )
     {
     }
 

include/boost/smart_ptr/shared_ptr.hpp

@@ -374,16 +374,27 @@ public:
     }
 
     //
-    // Requirements: D's copy constructor must not throw
+    // Requirements: D's copy/move constructors must not throw
     //
     // shared_ptr will release p by calling d(p)
     //
 
+#if !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
+
+    template<class Y, class D> shared_ptr( Y * p, D d ): px( p ), pn( p, static_cast< D&& >( d ) )
+    {
+        boost::detail::sp_deleter_construct( this, p );
+    }
+
+#else
+
     template<class Y, class D> shared_ptr( Y * p, D d ): px( p ), pn( p, d )
     {
         boost::detail::sp_deleter_construct( this, p );
     }
 
+#endif
+
 #if !defined( BOOST_NO_CXX11_NULLPTR )
 
     template<class D> shared_ptr( boost::detail::sp_nullptr_t p, D d ): px( p ), pn( p, d )
@@ -693,11 +704,22 @@ public:
         this_type( p ).swap( *this );
     }
 
+#if !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
+
+    template<class Y, class D> void reset( Y * p, D d )
+    {
+        this_type( p, static_cast< D&& >( d ) ).swap( *this );
+    }
+
+#else
+
     template<class Y, class D> void reset( Y * p, D d )
     {
         this_type( p, d ).swap( *this );
     }
 
+#endif
+
     template<class Y, class D, class A> void reset( Y * p, D d, A a )
     {
         this_type( p, d, a ).swap( *this );

test/Jamfile

@@ -410,3 +410,4 @@ run owner_hash_test.cpp ;
 run sp_unordered_test.cpp ;
 
 run sp_unique_ptr_test2.cpp ;
+run sp_move_only_deleter.cpp ;

test/sp_move_only_deleter.cpp

@@ -0,0 +1,106 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/shared_ptr.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config.hpp>
+#include <boost/config/pragma_message.hpp>
+#include <memory>
+#include <utility>
+
+#if defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
+
+BOOST_PRAGMA_MESSAGE("Skipping test because BOOST_NO_CXX11_RVALUE_REFERENCES is defined")
+int main() {}
+
+#else
+
+struct Y
+{
+    static int instances;
+
+    bool deleted_;
+
+    Y(): deleted_( false )
+    {
+        ++instances;
+    }
+
+    ~Y()
+    {
+        BOOST_TEST( deleted_ );
+        --instances;
+    }
+
+private:
+
+    Y( Y const & );
+    Y & operator=( Y const & );
+};
+
+int Y::instances = 0;
+
+struct YD
+{
+    bool moved_;
+
+    YD(): moved_( false )
+    {
+    }
+
+    YD( YD&& r ): moved_( false )
+    {
+        r.moved_ = true;
+    }
+
+    void operator()( Y* p ) const
+    {
+        BOOST_TEST( !moved_ );
+
+        if( p )
+        {
+            p->deleted_ = true;
+            delete p;
+        }
+    }
+
+private:
+
+    YD( YD const & );
+    YD & operator=( YD const & );
+};
+
+int main()
+{
+    BOOST_TEST( Y::instances == 0 );
+
+    {
+        YD del;
+        boost::shared_ptr<Y> p( new Y, std::move( del ) );
+
+        BOOST_TEST( Y::instances == 1 );
+        BOOST_TEST( del.moved_ );
+
+        p.reset( new Y, YD() );
+
+        BOOST_TEST( Y::instances == 1 );
+
+        p = boost::shared_ptr<Y>( new Y, YD() );
+
+        BOOST_TEST( Y::instances == 1 );
+
+        YD del2;
+        p.reset( new Y, std::move( del2 ) );
+
+        BOOST_TEST( Y::instances == 1 );
+        BOOST_TEST( del2.moved_ );
+
+        p.reset();
+        BOOST_TEST( Y::instances == 0 );
+    }
+
+    return boost::report_errors();
+}
+
+#endif