Check if flag contains any value of other flag

April 20, 2022

I would like compare two flags and see if they have any common value.
I’ld like having an extension method as weel in order to "speed up" coding (I’m going to use it often and on various Enum types). How can I?
This code tell me:

operator ‘&’ cannot be applied to operands of type enum and enum

public enum Tag
{
    Value1 = 1,
    Value2 = 2,
    Value3 = 4,
    Value4 = 8,
    Value5 = 16
}

public static class FlagExt
{
    public static bool HasAny(this Enum me, Enum other)
    {
        return (me & other) != 0;
    }
}

public class Program
{
    public static void Main()
    {
        Tag flag1 = Tag.Value1 | Tag.Value2 | Tag.Value3;
        Tag flag2 = Tag.Value2 | Tag.Value3 | Tag.Value4;
        
        Console.WriteLine(flag1.HasAny(flag2)); // it should returns true. flag1.HasFlag(flag2) returns false.
    }
}

I tried this as well:

    return (((int)me) & ((int)other)) != 0;

but it raises the error:

Cannot convert type ‘System.Enum’ to ‘int’

>Solution :

As per this answer (How to convert from System.Enum to base integer?)

You will need to wrap this code with an exception handler or otherwise ensure that both enums hold an integer.

public static class FlagExt
{
    public static bool HasAny(this Enum me, Enum other)
    {
        return (Convert.ToInt32(me) & Convert.ToInt32(other)) != 0;
    }
}