reduction is too strict for ⟨MethodReference → alpha⟩

[Stephan Herrmann]

Yes, that explains, thanks,
Stephan

On 12/19/2013 09:39 PM, Dan Smith wrote:
> The argument should not be treated as pertinent to applicability.  This statement from 15.12.2.2 is meant to apply to exact method references too:
>
> "If m is a generic method and the method invocation does not provide explicit type arguments, an explicitly-typed lambda expression ***or an exact method reference*** for which the corresponding target type (as derived from the signature of m) is a type parameter of m."
>
> (The part in asterisks is currently missing.)
>
> —Dan
>
> On Dec 19, 2013, at 9:39 AM, Stephan Herrmann <stephan.herrmann at berlin.de> wrote:
>
>>  From this program
>>
>>   interface Functional { int foo(); }
>>
>>   class X {
>>       static int bar() {
>>           return -1;
>>       }
>>       static <T> T consume(T t) { return null; }
>>
>>       public static void main(String[] args) {
>>           Functional f = consume(X::bar);
>>       }
>>   }
>>
>> we create this constraint:
>>
>>   ⟨X::bar → T#0⟩
>>
>> 18.2.1.2 says:
>>
>> "If T is not a functional interface type (9.8), or if T is a functional interface type but does not have a function type, the constraint reduces to false."
>>
>> Inference fails because T#0 (in inference variable) is not a functional interface type, nor does it have a sam.
>>
>> javac accepts the program, so it seems to use an additional reduction rule here?
>>
>> Stephan
>