& operator not work for enum

[LiveIsLive]

For example, run the code below and the button is still visible

<Button Visibility="{c:Binding '(io:FileAttributes.Directory &amp; io:FileAttributes.Directory) != io:FileAttributes.Directory'}" xmlns:c="clr-namespace:CalcBinding;assembly=CalcBinding" xmlns:io="clr-namespace:System.IO;assembly=mscorlib">Test</Button>