generics - Enum flags wrapper in C#

I am refactoring some code for several enum collections that support the [Flags] attribute.

I am trying to come up with a generic class that allows for common methods (adding, removing and checking enums exist in the collection etc).

I began with this code:

public class EnumFlags
{
    protected T collection;


    public void Add(T value)
    {
        this.collection = this.collection | value;
    }
}

However, I cannot use the | operator on type T. I cannot add a constraint for T to be an enum (where T : Enum is not allowed).

Any ideas to approaching this problem?