martin odersky | 21 Jun 00:53 2010

Fwd: Re: Explicit vs implicit return type Double

OK, tests passed. The next nightly should have the reverted semantics.
I'll see when we can roll the next RC.


 -- Martin

On Mon, Jun 21, 2010 at 12:41 AM, martin odersky <martin.odersky <at>> wrote:
> On Sun, Jun 20, 2010 at 11:20 PM, friedrich <f.esser <at>> wrote:
>> Sorry to be here again:
>> I have already posted the behavior here (under "esser")
> The strange thing is that I never got this mail in my reader (gmail).
> I checked again, and it is simply not there. Which is a pity because I
> think you have uncovered a serious unintended side-effect of the weak
> conformance rules in overloading resolution. The problem was that
> arguments of overloaded methods are required to conform weakly,
> whereas the result type was required to conform strongly. This favored
> the Float => Float addition method on an Int over the
> Int => Int method if the result type was Float. I was trying to be
> conservative in my change to weak conformance in that I required weak
> conformance only where it looked absolutely necessary. But it seems
> now that being conservative caused the problem we are looking at!
> I am just running the tests now to get an idea whether we can fix this
> by requiring weak conformance also for the return type. I believe that
> will work. The unfortunate aspect of all this is that we found out
> about this so late that we will need another RC to fix it. But it's
> better fix it now than ship 2.8 with broken method overloading.
> Cheers
>  -- Martin