Updated copyright

[libcds.git] / cds / container / impl / skip_list_set.h

diff --git a/cds/container/impl/skip_list_set.h b/cds/container/impl/skip_list_set.h
index 9de1eb5ec6c928fdaa389b7dee0189113826a4cf..ab075e9702448206e2d2264b320852ec485df84b 100644 (file)
--- a/cds/container/impl/skip_list_set.h
+++ b/cds/container/impl/skip_list_set.h
@@ -1,10 +1,37 @@
-//$$CDS-header$$
+/*
+    This file is a part of libcds - Concurrent Data Structures library

 
 

-#ifndef __CDS_CONTAINER_IMPL_SKIP_LIST_SET_H
-#define __CDS_CONTAINER_IMPL_SKIP_LIST_SET_H
+    (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
+
+    Source code repo: http://github.com/khizmax/libcds/
+    Download: http://sourceforge.net/projects/libcds/files/
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice, this
+      list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimer in the documentation
+      and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+    OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CDSLIB_CONTAINER_IMPL_SKIP_LIST_SET_H
+#define CDSLIB_CONTAINER_IMPL_SKIP_LIST_SET_H

 
 #include <cds/details/binary_functor_wrapper.h>
 
 #include <cds/details/binary_functor_wrapper.h>

-#include <cds/gc/guarded_ptr.h>

 #include <cds/container/details/guarded_ptr_cast.h>
 
 namespace cds { namespace container {
 #include <cds/container/details/guarded_ptr_cast.h>
 
 namespace cds { namespace container {


@@ -37,7 +64,7 @@ namespace cds { namespace container {
         - \p GC - Garbage collector used.
         - \p T - type to be stored in the list.
         - \p Traits - set traits, default is \p skip_list::traits.
         - \p GC - Garbage collector used.
         - \p T - type to be stored in the list.
         - \p Traits - set traits, default is \p skip_list::traits.

-            It is possible to declare option-based list with \p cds::container::skip_list::make_traits metafunction 
+            It is possible to declare option-based list with \p cds::container::skip_list::make_traits metafunction

             istead of \p Traits template argument.
 
         @warning The skip-list requires up to 67 hazard pointers that may be critical for some GCs for which
             istead of \p Traits template argument.
 
         @warning The skip-list requires up to 67 hazard pointers that may be critical for some GCs for which


@@ -125,6 +152,8 @@ namespace cds { namespace container {
         typedef typename traits::random_level_generator random_level_generator; ///< random level generator
         typedef typename traits::stat             stat;           ///< internal statistics type
 
         typedef typename traits::random_level_generator random_level_generator; ///< random level generator
         typedef typename traits::stat             stat;           ///< internal statistics type
 

+        static size_t const c_nHazardPtrCount = base_class::c_nHazardPtrCount; ///< Count of hazard pointer required for the skip-list
+

     protected:
         //@cond
         typedef typename maker::node_type           node_type;
     protected:
         //@cond
         typedef typename maker::node_type           node_type;


@@ -135,7 +164,7 @@ namespace cds { namespace container {
 
     public:
         /// Guarded pointer
 
     public:
         /// Guarded pointer

-        typedef cds::gc::guarded_ptr< gc, node_type, value_type, details::guarded_ptr_cast_set<node_type, value_type> > guarded_ptr;
+        typedef typename gc::template guarded_ptr< node_type, value_type, details::guarded_ptr_cast_set<node_type, value_type> > guarded_ptr;

 
     protected:
         //@cond
 
     protected:
         //@cond


@@ -156,7 +185,50 @@ namespace cds { namespace container {
         {}
 
     public:
         {}
 
     public:

+    ///@name Forward iterators (only for debugging purpose)
+    //@{

         /// Iterator type
         /// Iterator type

+        /**
+            The forward iterator has some features:
+            - it has no post-increment operator
+            - to protect the value, the iterator contains a GC-specific guard + another guard is required locally for increment operator.
+              For some GC (like as \p gc::HP), a guard is a limited resource per thread, so an exception (or assertion) "no free guard"
+              may be thrown if the limit of guard count per thread is exceeded.
+            - The iterator cannot be moved across thread boundary because it contains thread-private GC's guard.
+            - Iterator ensures thread-safety even if you delete the item the iterator points to. However, in case of concurrent
+              deleting operations there is no guarantee that you iterate all item in the list.
+              Moreover, a crash is possible when you try to iterate the next element that has been deleted by concurrent thread.
+
+            @warning Use this iterator on the concurrent container for debugging purpose only.
+
+            The iterator interface:
+            \code
+            class iterator {
+            public:
+                // Default constructor
+                iterator();
+
+                // Copy construtor
+                iterator( iterator const& src );
+
+                // Dereference operator
+                value_type * operator ->() const;
+
+                // Dereference operator
+                value_type& operator *() const;
+
+                // Preincrement operator
+                iterator& operator ++();
+
+                // Assignment operator
+                iterator& operator = (iterator const& src);
+
+                // Equality operators
+                bool operator ==(iterator const& i ) const;
+                bool operator !=(iterator const& i ) const;
+            };
+            \endcode
+        */

         typedef skip_list::details::iterator< typename base_class::iterator >  iterator;
 
         /// Const iterator type
         typedef skip_list::details::iterator< typename base_class::iterator >  iterator;
 
         /// Const iterator type


@@ -165,38 +237,39 @@ namespace cds { namespace container {
         /// Returns a forward iterator addressing the first element in a set
         iterator begin()
         {
         /// Returns a forward iterator addressing the first element in a set
         iterator begin()
         {

-            return iterator( base_class::begin() );
+            return iterator( base_class::begin());

         }
 
         /// Returns a forward const iterator addressing the first element in a set
         const_iterator begin() const
         {
         }
 
         /// Returns a forward const iterator addressing the first element in a set
         const_iterator begin() const
         {

-            return const_iterator( base_class::begin() );
+            return const_iterator( base_class::begin());

         }
 
         /// Returns a forward const iterator addressing the first element in a set
         const_iterator cbegin() const
         {
         }
 
         /// Returns a forward const iterator addressing the first element in a set
         const_iterator cbegin() const
         {

-            return const_iterator( base_class::cbegin() );
+            return const_iterator( base_class::cbegin());

         }
 
         /// Returns a forward iterator that addresses the location succeeding the last element in a set.
         iterator end()
         {
         }
 
         /// Returns a forward iterator that addresses the location succeeding the last element in a set.
         iterator end()
         {

-            return iterator( base_class::end() );
+            return iterator( base_class::end());

         }
 
         /// Returns a forward const iterator that addresses the location succeeding the last element in a set.
         const_iterator end() const
         {
         }
 
         /// Returns a forward const iterator that addresses the location succeeding the last element in a set.
         const_iterator end() const
         {

-            return const_iterator( base_class::end() );
+            return const_iterator( base_class::end());

         }
 
         /// Returns a forward const iterator that addresses the location succeeding the last element in a set.
         const_iterator cend() const
         {
         }
 
         /// Returns a forward const iterator that addresses the location succeeding the last element in a set.
         const_iterator cend() const
         {

-            return const_iterator( base_class::cend() );
+            return const_iterator( base_class::cend());

         }
         }

+    //@}

 
     public:
         /// Inserts new node
 
     public:
         /// Inserts new node


@@ -214,7 +287,7 @@ namespace cds { namespace container {
         bool insert( Q const& val )
         {
             scoped_node_ptr sp( node_allocator().New( random_level(), val ));
         bool insert( Q const& val )
         {
             scoped_node_ptr sp( node_allocator().New( random_level(), val ));

-            if ( base_class::insert( *sp.get() )) {
+            if ( base_class::insert( *sp.get())) {

                 sp.release();
                 return true;
             }
                 sp.release();
                 return true;
             }


@@ -247,47 +320,54 @@ namespace cds { namespace container {
             return false;
         }
 
             return false;
         }
 

-        /// Ensures that the item exists in the set
+        /// Updates the item

         /**
             The operation performs inserting or changing data with lock-free manner.
 
             If the \p val key not found in the set, then the new item created from \p val
         /**
             The operation performs inserting or changing data with lock-free manner.
 
             If the \p val key not found in the set, then the new item created from \p val

-            is inserted into the set. Otherwise, the functor \p func is called with the item found.
-            The functor \p Func should be a function with signature:
-            \code
-                void func( bool bNew, value_type& item, const Q& val );
-            \endcode
-            or a functor:
+            will be inserted into the set iff \p bInsert is \p true.
+            Otherwise, if \p val is found, the functor \p func will be called with the item found.
+
+            The functor \p Func signature:

             \code
                 struct my_functor {
                     void operator()( bool bNew, value_type& item, const Q& val );
                 };
             \endcode
             \code
                 struct my_functor {
                     void operator()( bool bNew, value_type& item, const Q& val );
                 };
             \endcode

-
-            with arguments:
+            where:

             - \p bNew - \p true if the item has been inserted, \p false otherwise
             - \p item - item of the set
             - \p bNew - \p true if the item has been inserted, \p false otherwise
             - \p item - item of the set

-            - \p val - argument \p key passed into the \p %ensure() function
+            - \p val - argument \p key passed into the \p %update() function

 
             The functor may change non-key fields of the \p item; however, \p func must guarantee
             that during changing no any other modifications could be made on this item by concurrent threads.
 
 
             The functor may change non-key fields of the \p item; however, \p func must guarantee
             that during changing no any other modifications could be made on this item by concurrent threads.
 

-            Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
-            \p second is true if new item has been added or \p false if the item with \p key
-            already is in the set.
+            Returns <tt> std::pair<bool, bool> </tt> where \p first is \p true if operation is successful,
+            i.e. the item has been inserted or updated,
+            \p second is \p true if new item has been added or \p false if the item with key equal to \p val
+            already exists.

 
             @warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
         */
         template <typename Q, typename Func>
 
             @warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
         */
         template <typename Q, typename Func>

-        std::pair<bool, bool> ensure( const Q& val, Func func )
+        std::pair<bool, bool> update( const Q& val, Func func, bool bInsert = true )

         {
             scoped_node_ptr sp( node_allocator().New( random_level(), val ));
         {
             scoped_node_ptr sp( node_allocator().New( random_level(), val ));

-            std::pair<bool, bool> bRes = base_class::ensure( *sp,
-                [&func, &val](bool bNew, node_type& node, node_type&){ func( bNew, node.m_Value, val ); });
+            std::pair<bool, bool> bRes = base_class::update( *sp,
+                [&func, &val](bool bNew, node_type& node, node_type&){ func( bNew, node.m_Value, val ); },
+                bInsert );

             if ( bRes.first && bRes.second )
                 sp.release();
             return bRes;
         }
             if ( bRes.first && bRes.second )
                 sp.release();
             return bRes;
         }

+        //@cond
+        template <typename Q, typename Func>
+        CDS_DEPRECATED("ensure() is deprecated, use update()")
+        std::pair<bool, bool> ensure( const Q& val, Func func )
+        {
+            return update( val, func, true );
+        }
+        //@endcond

 
         /// Inserts data of type \p value_type created in-place from <tt>std::forward<Args>(args)...</tt>
         /**
 
         /// Inserts data of type \p value_type created in-place from <tt>std::forward<Args>(args)...</tt>
         /**


@@ -297,7 +377,7 @@ namespace cds { namespace container {
         bool emplace( Args&&... args )
         {
             scoped_node_ptr sp( node_allocator().New( random_level(), std::forward<Args>(args)... ));
         bool emplace( Args&&... args )
         {
             scoped_node_ptr sp( node_allocator().New( random_level(), std::forward<Args>(args)... ));

-            if ( base_class::insert( *sp.get() )) {
+            if ( base_class::insert( *sp.get())) {

                 sp.release();
                 return true;
             }
                 sp.release();
                 return true;
             }


@@ -328,7 +408,8 @@ namespace cds { namespace container {
         template <typename Q, typename Less>
         bool erase_with( Q const& key, Less pred )
         {
         template <typename Q, typename Less>
         bool erase_with( Q const& key, Less pred )
         {

-            return base_class::erase_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >() );
+            CDS_UNUSED( pred );
+            return base_class::erase_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >());

         }
 
         /// Delete \p key from the set
         }
 
         /// Delete \p key from the set


@@ -367,6 +448,7 @@ namespace cds { namespace container {
         template <typename Q, typename Less, typename Func>
         bool erase_with( Q const& key, Less pred, Func f )
         {
         template <typename Q, typename Less, typename Func>
         bool erase_with( Q const& key, Less pred, Func f )
         {

+            CDS_UNUSED( pred );

             return base_class::erase_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >(),
                 [&f]( node_type const& node) { f( node.m_Value ); } );
         }
             return base_class::erase_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >(),
                 [&f]( node_type const& node) { f( node.m_Value ); } );
         }


@@ -374,13 +456,13 @@ namespace cds { namespace container {
         /// Extracts the item from the set with specified \p key
         /** \anchor cds_nonintrusive_SkipListSet_hp_extract
             The function searches an item with key equal to \p key in the set,
         /// Extracts the item from the set with specified \p key
         /** \anchor cds_nonintrusive_SkipListSet_hp_extract
             The function searches an item with key equal to \p key in the set,

-            unlinks it from the set, and returns it in \p result parameter.
-            If the item with key equal to \p key is not found the function returns \p false.
+            unlinks it from the set, and returns it as \p guarded_ptr.
+            If \p key is not found the function returns an empty guarded pointer.

 
             Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
 
             The item extracted is freed automatically by garbage collector \p GC
 
             Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
 
             The item extracted is freed automatically by garbage collector \p GC

-            when returned \ref guarded_ptr object will be destroyed or released.
+            when returned \p guarded_ptr object will be destroyed or released.

             @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
 
             Usage:
             @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
 
             Usage:


@@ -389,8 +471,8 @@ namespace cds { namespace container {
             skip_list theList;
             // ...
             {
             skip_list theList;
             // ...
             {

-                skip_list::guarded_ptr gp;
-                if ( theList.extract( gp, 5 ) ) {
+                skip_list::guarded_ptr gp(theList.extract( 5 ))
+                if (  gp ) {

                     // Deal with gp
                     // ...
                 }
                     // Deal with gp
                     // ...
                 }


@@ -399,9 +481,9 @@ namespace cds { namespace container {
             \endcode
         */
         template <typename Q>
             \endcode
         */
         template <typename Q>

-        bool extract( guarded_ptr& result, Q const& key )
+        guarded_ptr extract( Q const& key )

         {
         {

-            return base_class::extract_( result.guard(), key, typename base_class::key_comparator() );
+            return base_class::extract_( key, typename base_class::key_comparator());

         }
 
         /// Extracts the item from the set with comparing functor \p pred
         }
 
         /// Extracts the item from the set with comparing functor \p pred


@@ -414,19 +496,20 @@ namespace cds { namespace container {
             \p pred must imply the same element order as the comparator used for building the set.
         */
         template <typename Q, typename Less>
             \p pred must imply the same element order as the comparator used for building the set.
         */
         template <typename Q, typename Less>

-        bool extract_with( guarded_ptr& ptr, Q const& key, Less pred )
+        guarded_ptr extract_with( Q const& key, Less pred )

         {
         {

+            CDS_UNUSED( pred );

             typedef cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >  wrapped_less;
             typedef cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >  wrapped_less;

-            return base_class::extract_( ptr.guard(), key, cds::opt::details::make_comparator_from_less<wrapped_less>() );
+            return base_class::extract_( key, cds::opt::details::make_comparator_from_less<wrapped_less>());

         }
 
         /// Extracts an item with minimal key from the set
         /**
         }
 
         /// Extracts an item with minimal key from the set
         /**

-            The function searches an item with minimal key, unlinks it, and returns the item found in \p result parameter.
-            If the skip-list is empty the function returns \p false.
+            The function searches an item with minimal key, unlinks it, and returns pointer to the item found as \p guarded_ptr.
+            If the skip-list is empty the function returns an empty guarded pointer.

 
             The item extracted is freed automatically by garbage collector \p GC
 
             The item extracted is freed automatically by garbage collector \p GC

-            when returned \ref guarded_ptr object will be destroyed or released.
+            when returned \p guarded_ptr object will be destroyed or released.

             @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
 
             Usage:
             @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
 
             Usage:


@@ -435,8 +518,8 @@ namespace cds { namespace container {
             skip_list theList;
             // ...
             {
             skip_list theList;
             // ...
             {

-                skip_list::guarded_ptr gp;
-                if ( theList.extract_min( gp )) {
+                skip_list::guarded_ptr gp( theList.extract_min());
+                if ( gp ) {

                     // Deal with gp
                     //...
                 }
                     // Deal with gp
                     //...
                 }


@@ -444,18 +527,18 @@ namespace cds { namespace container {
             }
             \endcode
         */
             }
             \endcode
         */

-        bool extract_min( guarded_ptr& result)
+        guarded_ptr extract_min()

         {
         {

-            return base_class::extract_min_( result.guard() );
+            return base_class::extract_min_();

         }
 
         /// Extracts an item with maximal key from the set
         /**
         }
 
         /// Extracts an item with maximal key from the set
         /**

-            The function searches an item with maximal key, unlinks it, and returns the pointer to item found in \p result parameter.
-            If the skip-list is empty the function returns \p false.
+            The function searches an item with maximal key, unlinks it, and returns the pointer to item found as \p guarded_ptr.
+            If the skip-list is empty the function returns an empty guarded pointer.

 
             The item found is freed by garbage collector \p GC automatically
 
             The item found is freed by garbage collector \p GC automatically

-            when returned \ref guarded_ptr object will be destroyed or released.
+            when returned \p guarded_ptr object will be destroyed or released.

             @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
 
             Usage:
             @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
 
             Usage:


@@ -464,8 +547,8 @@ namespace cds { namespace container {
             skip_list theList;
             // ...
             {
             skip_list theList;
             // ...
             {

-                skip_list::guarded_ptr gp;
-                if ( theList.extract_max( gp )) {
+                skip_list::guarded_ptr gp( theList.extract_max());
+                if ( gp ) {

                     // Deal with gp
                     //...
                 }
                     // Deal with gp
                     //...
                 }


@@ -473,9 +556,9 @@ namespace cds { namespace container {
             }
             \endcode
         */
             }
             \endcode
         */

-        bool extract_max( guarded_ptr& result )
+        guarded_ptr extract_max()

         {
         {

-            return base_class::extract_max_( result.guard() );
+            return base_class::extract_max_();

         }
 
         /// Find the \p key
         }
 
         /// Find the \p key


@@ -523,6 +606,7 @@ namespace cds { namespace container {
         template <typename Q, typename Less, typename Func>
         bool find_with( Q& key, Less pred, Func f )
         {
         template <typename Q, typename Less, typename Func>
         bool find_with( Q& key, Less pred, Func f )
         {

+            CDS_UNUSED( pred );

             return base_class::find_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >(),
                 [&f]( node_type& node, Q& v ) { f( node.m_Value, v ); } );
         }
             return base_class::find_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >(),
                 [&f]( node_type& node, Q& v ) { f( node.m_Value, v ); } );
         }


@@ -530,45 +614,57 @@ namespace cds { namespace container {
         template <typename Q, typename Less, typename Func>
         bool find_with( Q const& key, Less pred, Func f )
         {
         template <typename Q, typename Less, typename Func>
         bool find_with( Q const& key, Less pred, Func f )
         {

+            CDS_UNUSED( pred );

             return base_class::find_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >(),
             return base_class::find_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >(),

-                                          [&f]( node_type& node, Q& v ) { f( node.m_Value, v ); } );
+                                          [&f]( node_type& node, Q const& v ) { f( node.m_Value, v ); } );

         }
         //@endcond
 
         }
         //@endcond
 

-        /// Find \p key
-        /** \anchor cds_nonintrusive_SkipListSet_find_val
-
+        /// Checks whether the set contains \p key
+        /**

             The function searches the item with key equal to \p key
             and returns \p true if it is found, and \p false otherwise.
             The function searches the item with key equal to \p key
             and returns \p true if it is found, and \p false otherwise.

-
-            Note the hash functor specified for class \p Traits template parameter
-            should accept a parameter of type \p Q that may be not the same as \ref value_type.

         */
         template <typename Q>
         */
         template <typename Q>

+        bool contains( Q const& key )
+        {
+            return base_class::contains( key );
+        }
+        //@cond
+        template <typename Q>
+        CDS_DEPRECATED("deprecated, use contains()")

         bool find( Q const& key )
         {
         bool find( Q const& key )
         {

-            return base_class::find( key );
+            return contains( key );

         }
         }

+        //@endcond

 
 

-        /// Finds \p key using \p pred predicate for searching
+        /// Checks whether the set contains \p key using \p pred predicate for searching

         /**
         /**

-            The function is an analog of \ref cds_nonintrusive_SkipListSet_find_val "find(Q const&)"
-            but \p pred is used for key comparing.
+            The function is similar to <tt>contains( key )</tt> but \p pred is used for key comparing.

             \p Less functor has the interface like \p std::less.
             \p Less must imply the same element order as the comparator used for building the set.
         */
         template <typename Q, typename Less>
             \p Less functor has the interface like \p std::less.
             \p Less must imply the same element order as the comparator used for building the set.
         */
         template <typename Q, typename Less>

+        bool contains( Q const& key, Less pred )
+        {
+            CDS_UNUSED( pred );
+            return base_class::contains( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >());
+        }
+        //@cond
+        template <typename Q, typename Less>
+        CDS_DEPRECATED("deprecated, use contains()")

         bool find_with( Q const& key, Less pred )
         {
         bool find_with( Q const& key, Less pred )
         {

-            return base_class::find_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >());
+            return contains( key, pred );

         }
         }

+        //@endcond

 
         /// Finds \p key and return the item found
         /** \anchor cds_nonintrusive_SkipListSet_hp_get
             The function searches the item with key equal to \p key
 
         /// Finds \p key and return the item found
         /** \anchor cds_nonintrusive_SkipListSet_hp_get
             The function searches the item with key equal to \p key

-            and assigns the item found to guarded pointer \p result.
-            The function returns \p true if \p key is found, and \p false otherwise.
-            If \p key is not found the \p result parameter is left unchanged.
+            and returns a guarded pointer to the item found.
+            If \p key is not found the function returns an empty guarded pointer.

 
             It is safe when a concurrent thread erases the item returned in \p result guarded pointer.
             In this case the item will be freed later by garbage collector \p GC automatically
 
             It is safe when a concurrent thread erases the item returned in \p result guarded pointer.
             In this case the item will be freed later by garbage collector \p GC automatically


@@ -581,8 +677,8 @@ namespace cds { namespace container {
             skip_list theList;
             // ...
             {
             skip_list theList;
             // ...
             {

-                skip_list::guarded_ptr gp;
-                if ( theList.get( gp, 5 ) ) {
+                skip_list::guarded_ptr gp( theList.get( 5 ));
+                if ( theList.get( 5 )) {

                     // Deal with gp
                     //...
                 }
                     // Deal with gp
                     //...
                 }


@@ -594,14 +690,14 @@ namespace cds { namespace container {
             should accept a parameter of type \p Q that can be not the same as \p value_type.
         */
         template <typename Q>
             should accept a parameter of type \p Q that can be not the same as \p value_type.
         */
         template <typename Q>

-        bool get( guarded_ptr& result, Q const& key )
+        guarded_ptr get( Q const& key )

         {
         {

-            return base_class::get_with_( result.guard(), key, typename base_class::key_comparator() );
+            return base_class::get_with_( key, typename base_class::key_comparator());

         }
 
         /// Finds \p key and return the item found
         /**
         }
 
         /// Finds \p key and return the item found
         /**

-            The function is an analog of \ref cds_nonintrusive_SkipListSet_hp_get "get( guarded_ptr&, Q const&)"
+            The function is an analog of \ref cds_nonintrusive_SkipListSet_hp_get "get(Q const&)"

             but \p pred is used for comparing the keys.
 
             \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
             but \p pred is used for comparing the keys.
 
             \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q


@@ -609,10 +705,11 @@ namespace cds { namespace container {
             \p pred must imply the same element order as the comparator used for building the set.
         */
         template <typename Q, typename Less>
             \p pred must imply the same element order as the comparator used for building the set.
         */
         template <typename Q, typename Less>

-        bool get_with( guarded_ptr& result, Q const& key, Less pred )
+        guarded_ptr get_with( Q const& key, Less pred )

         {
         {

+            CDS_UNUSED( pred );

             typedef cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >  wrapped_less;
             typedef cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >  wrapped_less;

-            return base_class::get_with_( result.guard(), key, cds::opt::details::make_comparator_from_less< wrapped_less >());
+            return base_class::get_with_( key, cds::opt::details::make_comparator_from_less< wrapped_less >());

         }
 
         /// Clears the set (not atomic).
         }
 
         /// Clears the set (not atomic).


@@ -622,7 +719,7 @@ namespace cds { namespace container {
             this sequence
             \code
             set.clear();
             this sequence
             \code
             set.clear();

-            assert( set.empty() );
+            assert( set.empty());

             \endcode
             the assertion could be raised.
 
             \endcode
             the assertion could be raised.
 


@@ -660,4 +757,4 @@ namespace cds { namespace container {
 
 }} // namespace cds::container
 
 
 }} // namespace cds::container
 

-#endif // #ifndef __CDS_CONTAINER_IMPL_SKIP_LIST_SET_H
+#endif // #ifndef CDSLIB_CONTAINER_IMPL_SKIP_LIST_SET_H