Now, as I have only today found this out myself, I felt I had to point out that the following statement is inaccurate:

“Unfortunately, removing a flag isn’t quite as easy.”

I believe you can use:

variable &= ~TestFlags.Sixteen;

The ( ~ ) operator, apparently, AND’s the _negative_ of the given flag.

Thanks, and enjoy!

public static TEnum Parse(string value, bool ignoreCase);

It can’t infer the enum type since it is a return value, but it still beats passing typeof(T). Oh well.

You can add to a flag enum using |=, which is very easy and concise:

variable |= TestFlags.Sixteen;

This will add the Sixteen flag to variable.

Unfortunately, removing a flag isn’t quite as easy. If you know, for sure, that the flag is set, you can do:

variable ^= TestFlags.Sixteen;

However, if the flag is not set, the above will add it (it flips the flag bit, not removes it).

There is no AddFlag/RemoveFlag in .NET 4, though.

Would be nice to have: HasFlag, AddFlag, RemoveFlag

It’s still a bit odd, usage wise, though – There’s no way to infer T, so you have to write:

Colors color = Enum
.Parse(colorString);

Also, TryParse is nice because it will not throw if there’s an error, which is a very useful feature. ]]> http://reedcopsey.com/2009/10/26/long-overdue-enum-goodness-in-net-4/#comment-127 Dan Atkinson Tue, 10 Nov 2009 20:05:59 +0000 http://reedcopsey.com/?p=77#comment-127 It has <T> on the class, but you can see that. It has <T> on the class, but you can see that.

public class Enum
{
public static T Parse(string value)
{
return (T)Enum.Parse(typeof(T), value, true);
}
}

Usage:
Enum.Parse(colorString);

Now, I don’t know about you, but I think mine is so much cleaner! If you really want, you can handle the try/catch in there, but if you’re concerned about it failing, then you should consider using a concrete class instead.

Something like this:

public flagged enum Days
{
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday
}

Days meetingDays = Days.Monday and Days.Tuesday and Days.Thursday;

if (Days.Friday in meetingDays)
{
}

Of course, I’m sure there’s an excellent reason as to why this wasn’t done like this… never really tried to figure it out.

Still, I wasn’t aware of this new feature. Thanks for the heads up!

Fernando