add original source

source/listing_7.14.cpp

@@ -0,0 +1,20 @@
+void push(T new_value)
+{
+    std::unique_ptr<T> new_data(new T(new_value));
+    counted_node_ptr new_next;
+    new_next.ptr=new node;
+    new_next.external_count=1;
+    for(;;)
+    {
+        node* const old_tail=tail.load();
+        T* old_data=nullptr;
+        if(old_tail->data.compare_exchange_strong(
+               old_data,new_data.get()))
+        {
+            old_tail->next=new_next;
+            tail.store(new_next.ptr);
+            new_data.release();
+            break;
+        }
+    }
+}