Examples of usage:

<xp:StackPanel Visibility="{Binding Path=[variantType.steps~conversion], Converter={StaticResource ValueConverter}, ConverterParameter=Crop?Visible:?Collapsed}">

<xp:TextBlock Text="{Binding Path=[dataSrc.priority]}" FontWeight="Bold"  Visibility="{Binding Path=[dataSrc.priority], Converter={StaticResource ValueConverter}, ConverterParameter=-1?Collapsed:?Visible}"/>