pool: add clone and move assignment operators

pool.hpp

@@ -62,7 +62,35 @@ namespace cruft {
 
 
         //---------------------------------------------------------------------
-        pool& operator= (pool&&);
+        pool& operator= (pool &&rhs)
+        {
+            std::swap (m_available, rhs.m_available);
+            std::swap (m_store,     rhs.m_store);
+            std::swap (m_capacity,  rhs.m_capacity);
+
+            return *this;
+        }
+
+
+        //---------------------------------------------------------------------
+        pool clone (void) const
+        {
+            pool res (m_capacity);
+            memcpy (res.m_store, m_store, sizeof (T) * m_capacity);
+
+            res.m_available = m_available.clone ();
+
+            // Rebase the pointers to available data so they point into the
+            // cloned object.
+            auto offset = reinterpret_cast<uintptr_t> (res.m_store) - reinterpret_cast<uintptr_t> (m_store);
+            auto data   = res.m_available.store (
+                decltype(res.m_available)::contract::I_HAVE_LOCKED_THIS_STRUCTURE
+            );
+            for (auto &ptr: data)
+                ptr = reinterpret_cast<void*> (reinterpret_cast<uintptr_t> (ptr) + offset);
+
+            return res;
+        }
 
 
         //---------------------------------------------------------------------