On 4/11/14, 11:32 AM, Walter Bright wrote:
On 4/11/2014 4:18 AM, Jonathan M Davis wrote:
I don't see much point to enums if they're not intended to list
all of their values.
Again, bit masks, Color, etc., and to provide a simple integral type
that behaves like an integral type yet can be overloaded and type checked.
The point here is to not hurt most for the benefit of the few. I think
insisting on these use cases is missing that point.
Andrei has pointed out that these uses are unsound if you desire that
the enumeration lists all possible values, and he's right. But I don't
think that automatically makes them pointless.
Soundness is a Big Deal(tm). It's also a false choice that assumes no
correct design is possible. The fact that we're willing to trade
soundness for... for what? For saving us the small effort of designing
the feature right? That's very un-D-y.
Heck, look at the "StorageClass" typedef in dmd's source code, and the
list of STC macro definitions. That would make a nice D enum, and have
some type safety too. It would be much more sound than the C method used.
That's but one anecdote. There are plenty of enums (e.g. tokens) in dmd
alone that are not flags.
Again: I'm fine with "it's not essential and urgh we kinda botched final
switch so we'll go with what we have although it's kind of a bummer"...
but claiming it's actually good, that I take issue with.
Andrei
