can C# enums be declared as of bool type?

Question

Hi,

Can I declare c# enum as bool like:

enum Result : bool
{
    pass = true,
    fail = false
}

Answer 1

It says

The approved types for an enum are byte, sbyte, short, ushort, int, uint, long, or ulong.

enum (C# Reference)

Answer 2

Hi, if you need your enum to contain boolean data in addition to the enum constant's type value, you could add a simple attribute to your enum, taking a boolean value. Then you can add an extension method for your enum that fetches the attribute and returns its boolean value.

public class MyBoolAttribute: Attribute
{
        public MyBoolAttribute(bool val)
        {
            Passed = val;
        }

        public bool Passed
        {
            get;
            set;
        }
}

public enum MyEnum
{
        [MyBoolAttribute(true)]
        Passed,
        [MyBoolAttribute(false)]
        Failed,
        [MyBoolAttribute(true)]
        PassedUnderCertainCondition,

        ... and other enum values

}

/* the extension method */    
public static bool DidPass(this Enum en)
{
       MyBoolAttribute attrib = GetAttribute<MyBoolAttribute>(en);
       return attrib.Passed;
}

/* general helper method to get attributes of enums */
public static T GetAttribute<T>(Enum en) where T : Attribute
{
       Type type = en.GetType();
       MemberInfo[] memInfo = type.GetMember(en.ToString());
       if (memInfo != null && memInfo.Length > 0)
       {
             object[] attrs = memInfo[0].GetCustomAttributes(typeof(T),
             false);

             if (attrs != null && attrs.Length > 0)
                return ((T)attrs[0]);

       }
       return null;
}

Answer 3

What about:

class Result
    {
        private Result()
        {
        }
        public static Result OK = new Result();
        public static Result Error = new Result();
        public static implicit operator bool(Result result)
        {
            return result == OK;
        }
        public static implicit operator Result( bool b)
        {
            return b ? OK : Error;
        }
    }

You can use it like Enum or like bool, for example var x = Result.OK; Result y = true; if(x) ... or if(y==Result.OK)