Improved variance for generic classes and interfaces

Brian Goetz brian.goetz at
Mon Jun 2 16:57:45 UTC 2014

Actually, the main value here to API designers is that what would ordinarily be a hard-to-correct mistake (defining a method to take Consumer<T> rather than Consumer<? super T>) would no longer be a mistake.  For API designers, there’s not much to learn, just a way of saying those who don’t fully understand generics (which is most of us) from some inevitable mistakes.  

On Jun 2, 2014, at 9:33 AM, Paul Benedict <pbenedict at> wrote:

> For anyone here who likes API designing, take a look at this new proposal
> (for JDK 9?):
> PS: I found the PDF references at the ticket's end to be quite insightful.
> Cheers,
> Paul

More information about the coin-dev mailing list