removed test for self-move

src/polymesh/detail/unique_array.hh

@@ -26,12 +26,10 @@ struct unique_array
     }
     unique_array& operator=(unique_array&& rhs) noexcept
     {
-        if (this != &rhs)
-        {
+        // self-move results in moved-from state
         delete[] ptr;
         ptr = rhs.ptr;
         rhs.ptr = nullptr;
-        }
 
         return *this;
     }