[Boost-commit] svn:boost r44077 - in branches/unordered/trunk/boost: . unordered/detail

From: daniel_james_at_[hidden]
Date: 2008-04-06 15:48:59

Author: danieljames
Date: 2008-04-06 15:48:59 EDT (Sun, 06 Apr 2008)
New Revision: 44077
URL: http://svn.boost.org/trac/boost/changeset/44077

Log:
Do move assignment 'properly'.
Text files modified: 
   branches/unordered/trunk/boost/unordered/detail/hash_table_impl.hpp |    53 +++++++++++++++++++++++++++++++++++++++ 
   branches/unordered/trunk/boost/unordered_map.hpp                    |     6 +---                                    
   branches/unordered/trunk/boost/unordered_set.hpp                    |     6 +---                                    
   3 files changed, 56 insertions(+), 9 deletions(-)

Modified: branches/unordered/trunk/boost/unordered/detail/hash_table_impl.hpp
==============================================================================
--- branches/unordered/trunk/boost/unordered/detail/hash_table_impl.hpp	(original)
+++ branches/unordered/trunk/boost/unordered/detail/hash_table_impl.hpp	2008-04-06 15:48:59 EDT (Sun, 06 Apr 2008)
@@ -365,6 +365,12 @@
             }
 #endif
 
+            // no throw
+            ~BOOST_UNORDERED_TABLE_DATA()
+            {
+                if(buckets_) delete_buckets();
+            }
+
             void create_buckets() {
                 // The array constructor will clean up in the event of an
                 // exception.
@@ -385,7 +391,7 @@
             }
 
             // no throw
-            ~BOOST_UNORDERED_TABLE_DATA()
+            void delete_buckets()
             {
                 if(buckets_) {
                     bucket_ptr begin = cached_begin_bucket_;
@@ -420,6 +426,16 @@
                 std::swap(size_, other.size_);
             }
 
+            // no throw
+            void move(BOOST_UNORDERED_TABLE_DATA&& other)
+            {
+                delete_buckets();
+                buckets_ = other.buckets_;
+                bucket_count_ = other.bucket_count_;
+                cached_begin_bucket_ = other.cached_begin_bucket_;
+                size_ = other.size_;
+            }
+
             // Return the bucket for a hashed value.
             //
             // no throw
@@ -1237,6 +1253,41 @@
                 x.calculate_max_load();
             }
 
+            // Move
+            //
+            // ----------------------------------------------------------------
+            //
+            // Strong exception safety (might change unused function objects)
+            //
+            // Can throw if hash or predicate object's copy constructor throws
+            // or if allocators are unequal.
+
+            void move(BOOST_UNORDERED_TABLE&& x)
+            {
+                // This only effects the function objects that aren't in use
+                // so it is strongly exception safe, via. double buffering.
+                functions_ptr new_func_this = copy_functions(x);       // throws
+
+                if(data_.allocators_ == x.data_.allocators_) {
+                    data_.move(x.data_); // no throw
+                }
+                else {
+                    // Create new buckets in separate HASH_TABLE_DATA objects
+                    // which will clean up if anything throws an exception.
+                    // (all can throw, but with no effect as these are new objects).
+                    data new_this(data_, x.min_buckets_for_size(x.data_.size_));
+                    copy_buckets(x.data_, new_this, this->*new_func_this);
+
+                    // Start updating the data here, no throw from now on.
+                    data_.move(new_this);
+                }
+
+                // We've made it, the rest is no throw.
+                mlf_ = x.mlf_;
+                func_ = new_func_this;
+                calculate_max_load();
+            }
+
         private:
 
             functions const& current_functions() const

Modified: branches/unordered/trunk/boost/unordered_map.hpp
==============================================================================
--- branches/unordered/trunk/boost/unordered_map.hpp	(original)
+++ branches/unordered/trunk/boost/unordered_map.hpp	2008-04-06 15:48:59 EDT (Sun, 06 Apr 2008)
@@ -112,11 +112,10 @@
         {
         }
 
-// TODO: Do this properly?
 #if defined(BOOST_HAS_RVALUE_REFS)
         unordered_map& operator=(unordered_map&& x)
         {
-            swap(x);
+            base.move(x.base);
             return *this;
         }
 #endif
@@ -457,11 +456,10 @@
         {
         }
 
-// TODO: Do this properly?
 #if defined(BOOST_HAS_RVALUE_REFS)
         unordered_multimap& operator=(unordered_multimap&& x)
         {
-            swap(x);
+            base.move(x.base);
             return *this;
         }
 #endif

Modified: branches/unordered/trunk/boost/unordered_set.hpp
==============================================================================
--- branches/unordered/trunk/boost/unordered_set.hpp	(original)
+++ branches/unordered/trunk/boost/unordered_set.hpp	2008-04-06 15:48:59 EDT (Sun, 06 Apr 2008)
@@ -109,11 +109,10 @@
         {
         }
 
-// TODO: Do this properly?
 #if defined(BOOST_HAS_RVALUE_REFS)
         unordered_set& operator=(unordered_set&& x)
         {
-            swap(x);
+            base.move(x.base);
             return *this;
         }
 #endif
@@ -425,11 +424,10 @@
         {
         }
 
-// TODO: Do this properly?
 #if defined(BOOST_HAS_RVALUE_REFS)
         unordered_multiset& operator=(unordered_multiset&& x)
         {
-            swap(x);
+            base.move(x.base);
             return *this;
         }
 #endif