Draft proposal: allow the use of relational operators on Comparable classes

Joshua Bloch jjb at google.com
Thu Mar 12 12:20:39 PDT 2009


Arguably it's a bit too late: the marker (or whatever) should have triggered
whether the enum implemented the Comparable interface as well:(


On Thu, Mar 12, 2009 at 12:19 PM, Alex Miller <alexdmiller at yahoo.com> wrote:

> Kevin Bourrillion <kevinb at google.com> said:
> > But focusing on enum types sidesteps one set of problems in favor of
> > another.  That being that most user-defined enum types do not actually
> have
> > any logical order, and many that _seem_ to have an order do not actually
> > have that order guaranteed.
> I would love to have the relational operators on enums...when it makes
> sense.  What if there was a marker interface that your enum could implement?
>  Something like OrderedEnum?
> I suppose it might be bad form to have the language behavior as to whether
> something is legal be dependent on a marker interface.  But you guys are the
> experts.
> Alex

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