Which is the currently-accepted best practice in terms of C# enum usage, a bitwise [Flags] Enum (compared using | and &) or an IEnumerable of enum values? I'm thinking both from a code-conciseness perspective and from a maintenance perspective.
The only downside to using the Flags approach that I can think of is the inability to enumerate the values without doing the reverse enumeration:
var possibleValues = Enum.GetValues(typeof(MyEnum)).Cast<MyEnum>();
var applicableValues = possibleValues.Where(x => (containerClass.EnumProperty & x) == x);
Whereas obviously the IEnumerable is easier to query.
EDIT:
As svick rightly pointed out, the IEnumerable would be perhaps the wrong collection to use, an ISet might be a better example.