Static methods of generic classes are treated differently

[Archie Cobbs]

Looks like a legitimate bug to me...

You'd think how the compiler treats a static method reference shouldn't be
at all determined by whether the class containing that static method is
generic or not...

I've created https://bugs.openjdk.org/browse/JDK-8309767 to track this.

-Archie

On Fri, Jun 9, 2023 at 11:59 AM Ethan McCue <ethan at mccue.dev> wrote:

> Following up on this just to see if there is an explanation of some sort I
> am missing.
>
> On Sun, Apr 30, 2023 at 8:40 AM Ethan McCue <ethan at mccue.dev> wrote:
>
>> I've run into either a corner case in type resolution or a compiler bug
>> and I'm not sure which.
>>
>> In an expression context, if a static method is referenced from a generic
>> class then it won't properly target overloads that require primitive
>> wrapper unboxing.
>>
>> package org.example;
>>
>> import java.time.Month;
>> import java.util.function.Supplier;
>>
>>
>> interface A {
>>     static int f() {
>>         return 1;
>>     }
>> }
>>
>> interface B<T> {
>>     static int f() {
>>         return 2;
>>     }
>> }
>>
>> final class C {
>>     static int f() {
>>         return 3;
>>     }
>> }
>>
>> final class D<T> {
>>     static int f() {
>>         return 4;
>>     }
>> }
>>
>>
>> public class Main {
>>     static void h(Month b) {}
>>     static void h(int b) {}
>>
>>     static <T> T g(Supplier<? extends T> d) {
>>         return d.get();
>>     }
>>
>>
>>     public static void main(String[] args) {
>>         // Compiles
>>         h(
>>                 g(A::f)
>>         );
>>
>>         // Doesn't compile
>>         h(
>>                 g(B::f)
>>         );
>>
>>         // Compiles
>>         var r1 = g(B::f);
>>         h(r1);
>>
>>         // Compiles
>>         h(
>>                 g(C::f)
>>         );
>>
>>         // Doesn't compile
>>         h(
>>                 g(D::f)
>>         );
>>
>>         // Compiles
>>         var r2 = g(D::f);
>>         h(r2);
>>     }
>> }
>>
>

-- 
Archie L. Cobbs
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