movable exempt_ptr: LazyList

[libcds.git] / cds / container / lazy_kvlist_rcu.h

diff --git a/cds/container/lazy_kvlist_rcu.h b/cds/container/lazy_kvlist_rcu.h
index b460c6d61277b519fcf619a1424c6e855ef42ba7..caae0c704083558a5ada5d51c185e631ca7375d7 100644 (file)
--- a/cds/container/lazy_kvlist_rcu.h
+++ b/cds/container/lazy_kvlist_rcu.h
@@ -121,9 +121,9 @@ namespace cds { namespace container {
 
     public:
         /// pointer to extracted node
-        typedef cds::urcu::exempt_ptr< gc, node_type, value_type, typename maker::intrusive_traits::disposer,
+        using exempt_ptr = cds::urcu::exempt_ptr< gc, node_type, value_type, typename maker::intrusive_traits::disposer,
             cds::urcu::details::conventional_exempt_pair_cast<node_type, value_type>
-        > exempt_ptr;
+        >;
 
     protected:
         //@cond
@@ -513,13 +513,13 @@ namespace cds { namespace container {
         /**
         @anchor cds_nonintrusive_LazyKVList_rcu_extract
             The function searches an item with key equal to \p key in the list,
-            unlinks it from the list, and returns pointer to an item found in \p dest argument.
-            If \p key is not found the function returns \p false.
+            unlinks it from the list, and returns \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the item found.
+            If \p key is not found the function returns an empty \p exempt_ptr.
 
             @note The function does NOT call RCU read-side lock or synchronization,
             and does NOT dispose the item found. It just excludes the item from the list
             and returns a pointer to item found.
-            You should lock RCU before calling this function.
+            You should manually lock RCU before calling this function.
 
             \code
             #include <cds/urcu/general_buffered.h>
@@ -538,7 +538,8 @@ namespace cds { namespace container {
 
                 // Now, you can apply extract function
                 // Note that you must not delete the item found inside the RCU lock
-                if ( theList.extract( p, 10 )) {
+                p = theList.extract( 10 );
+                if ( !p ) {
                     // do something with p
                     ...
                 }
@@ -549,10 +550,9 @@ namespace cds { namespace container {
             \endcode
         */
         template <typename K>
-        bool extract( exempt_ptr& dest, K const& key )
+        exempt_ptr extract( K const& key )
         {
-            dest = extract_at( head(), key, intrusive_key_comparator() );
-            return !dest.empty();
+            return exempt_ptr( extract_at( head(), key, intrusive_key_comparator()));
         }
 
         /// Extracts an item from the list using \p pred predicate for searching
@@ -563,10 +563,9 @@ namespace cds { namespace container {
             \p pred must imply the same element order as \ref key_comparator.
         */
         template <typename K, typename Less>
-        bool extract_with( exempt_ptr& dest, K const& key, Less pred )
+        exempt_ptr extract_with( K const& key, Less pred )
         {
-            dest = extract_at( head(), key, typename maker::template less_wrapper<Less>::type() );
-            return !dest.empty();
+            return exempt_ptr( extract_at( head(), key, typename maker::template less_wrapper<Less>::type() ));
         }
 
         /// Finds the key \p key