Is flags enum needed in Phobos?

[Michael]

On Tuesday, 25 September 2012 at 17:13:44 UTC, Denis Shelomovskij 
wrote:
> .NET has FlagsAttribute, Java has EnumSet. Looks like we need 
> this too. How about to add a library solution to Phobos?
>
+1.


> Also I'm not sure:
> * Should we support converting from a number to a flag enum?
+1.

> * If so, should we support values not from enum flags or throw 
> exceptions (it may be configurable)?

http://msdn.microsoft.com/en-us/library/system.enum.aspx
IsDefined method.

> * Is `flagEnum` an appropriate name?
Just "enum" with additional methods like: HasFlag, IsFlag