parallel/stack: add move operators

parallel/stack.hpp

@@ -32,8 +32,31 @@ namespace cruft::parallel {
         stack (stack const &) = delete;
         stack& operator=(stack const &) = delete;
 
-        stack (stack &&);
+        stack (stack &&rhs):
-        stack& operator= (stack &&);
+            stack (0)
+        {
+            swap (rhs);
+        }
+
+        stack& operator= (stack &&rhs)
+        {
+            swap (rhs);
+            return *this;
+        }
+
+        void swap (stack &rhs)
+        {
+            std::lock_guard lk0 (m_lock);
+            std::lock_guard lk1 (rhs.m_lock);
+
+            auto tmp = m_cursor.load ();
+            m_cursor = rhs.m_cursor.load ();
+            rhs.m_cursor = tmp;
+
+            std::swap (m_store,  rhs.m_store);
+            std::swap (m_lock,   rhs.m_lock);
+        }
+
 
         stack (std::size_t capacity)
             : m_cursor (0)
@@ -42,7 +65,6 @@ namespace cruft::parallel {
             CHECK_GT (capacity, 0u);
         }
 
-
         /// Move the value from the top of the stack into an output pointer.
         ///
         /// The internal object will be destroyed after the output has been set.