Add shared_ptr constructor taking std::unique_ptr. Refs #6625.

[SVN r81131]

include/boost/smart_ptr/detail/shared_count.hpp

@@ -37,6 +37,10 @@
 #include <functional>       // std::less
 #include <new>              // std::bad_alloc
 
+#if !defined( BOOST_NO_CXX11_SMART_PTR )
+# include <boost/utility/addressof.hpp>
+#endif
+
 namespace boost
 {
 
@@ -56,6 +60,38 @@ template< class D > struct sp_inplace_tag
 {
 };
 
+#if !defined( BOOST_NO_CXX11_SMART_PTR )
+
+template< class T > class sp_reference_wrapper
+{ 
+public:
+
+    explicit sp_reference_wrapper( T & t): t_( boost::addressof( t ) )
+    {
+    }
+
+    template< class Y > void operator()( Y * p ) const
+    {
+        (*t_)( p );
+    }
+
+private:
+
+    T * t_;
+};
+
+template< class D > struct sp_convert_reference
+{
+    typedef D type;
+};
+
+template< class D > struct sp_convert_reference< D& >
+{
+    typedef sp_reference_wrapper< D > type;
+};
+
+#endif
+
 class weak_count;
 
 class shared_count
@@ -300,6 +336,33 @@ public:
 
 #endif 
 
+#if !defined( BOOST_NO_CXX11_SMART_PTR )
+
+    template<class Y, class D>
+    explicit shared_count( std::unique_ptr<Y, D> & r ): pi_( 0 )
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        , id_(shared_count_id)
+#endif
+    {
+        typedef typename sp_convert_reference<D>::type D2;
+
+        D2 d2( r.get_deleter() );
+        pi_ = new sp_counted_impl_pd< Y*, D2 >( r.get(), d2 );
+
+#ifdef BOOST_NO_EXCEPTIONS
+
+        if( pi_ == 0 )
+        {
+            boost::throw_exception( std::bad_alloc() );
+        }
+
+#endif
+
+        r.release();
+    }
+
+#endif
+
     ~shared_count() // nothrow
     {
         if( pi_ != 0 ) pi_->release();

include/boost/smart_ptr/shared_ptr.hpp

@@ -298,6 +298,18 @@ public:
 
 #endif // BOOST_NO_AUTO_PTR
 
+#if !defined( BOOST_NO_CXX11_SMART_PTR )
+
+    template< class Y, class D >
+    shared_ptr( std::unique_ptr< Y, D > && r): px( r.get() ), pn()
+    {
+        Y * tmp = r.get();
+        pn = boost::detail::shared_count( r );
+        boost::detail::sp_enable_shared_from_this( this, tmp, tmp );
+    }
+
+#endif
+
     // assignment
 
     shared_ptr & operator=( shared_ptr const & r ) // never throws