Issues making a generic class with System.Enum as a parameter [modified]

[carbon_golem]

What I'd like to be able to do is make a generic class for hardware status words where every bit in the word corresponds to a boolean named flag. I'd like to have something that would take advantage of the underlying type of the enum as well as some attributes that I'm tagging onto the enum. I thought I'd be able to do that, but I'm not having very much luck at it. I guess the enum is just being used as a template which is what I want. The question is, is it possible to take advantage of some of the enum features in a generic class? Example target code:enum AlarmTemplate : byte { [Description("High Liquid Level")] HighLevel, [Description("Low Liquid Level")] LowLevel } Byte theStatus = 0xA5; StatusWord<<AlarmTemplate>> word = new StatusWord<<AlarmTemplate>>(theStatus); // where i can pass in the underlying type as an initializer word.Bit[AlarmTemplate.HighLevel] = false; // Indexer Byte temp = word.UnderlyingValue; // returns the enum's underlying type
I've always made custom classes to support all of these things, and lately I'm getting tired of it. Any ideas? Scott P

“It is practically impossible to teach good programming to students that have had a prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration.” -Edsger Dijkstra

modified on Thursday, May 8, 2008 11:03 AM

[S Senthil Kumar]

I don't know if I understood you correctly, but how about something like this

class StatusWord<T, U> where T : struct where U : struct
{
    U val;

    public StatusWord(U val)
    {
        this.val = val;
    }

    public bool this\[T t\]
    {
        set { val  = val | 0x001; }
    }

    public U Val
    {
        get { return val; }
    }
}

Regards Senthil [MVP - Visual C#] _____________________________ My Blog | My Articles | My Flickr | WinMacro

[PIEBALDconsult]

The code you show seems more or less OK (other than the doubled < and >), but I don't understand what you want to accomplish.

carbon_golem wrote:

where every bit in the word corresponds to a boolean named flag

Will the FlagsAttribute be of use?

[carbon_golem]

I put the double <<>> to make the CP html generator show at least that it was generic. What I want to do is define named bits in a generic way. The named bits would be of standard lengths, 8, 16, 32, 64. I hoped to use an enum to provide a templating mechanism to do this, but so far no luck, and the solutions I have worked out aren't very type safe. What this is for is representing bit fields in embedded device logs. Here is my latest. A lot of it is shetchy, but...public class StatusField where T : struct { #region Members private T template; private ValueType sword; #endregion private StatusField(ValueType initialValue) { template = new T(); if (template is Enum) { Type t = template.GetType(); if (t.GetCustomAttributes(typeof(FlagsAttribute), false).Length == 0) { throw new System.InvalidCastException("Requires Enum that defines FlagsAttribute"); } sword = initialValue; } else { throw new System.InvalidCastException("Could not convert generic type"); } } public Object UnderlyingValue { get { return sword; } set { sword = (ValueType)value; } } public Boolean this[T index] { get { if (Enum.IsDefined(typeof(T), index)) { Object x = Convert.ChangeType(index, typeof(Int64)); Int64 temp1 = (Int64)x; Object y = Convert.ChangeType(sword, typeof(Int64)); Int64 temp2 = (Int64)y; return (temp1 & temp2) == temp1; } else { throw new IndexOutOfRangeException("Field is not defined"); } } set { if (Enum.IsDefined(typeof(T), index)) { // setter not defined } else { throw new IndexOutOfRangeException("Field is not defined"); } } } public static StatusField New(ValueType value) { return new StatusField(value); } }
And Usage: StatusField field = StatusField.New(Alarms.Battery | Alarms.Motion);

[PIEBALDconsult]

I suspect you need the FlagsAttribute, but I'm still unclear on what you are trying to do.