> On Jan 27, 2022, at 8:09 AM, Dan Heidinga <heidi...@redhat.com> wrote:
>
>>> 2) What is the rationale behind the return type restrictions on <new>
>>> methods?
> ....
>> Treatment of <new> methods is still unresolved, so this (and the JEP) is
>> just describing one possible approach. I tried to reach a conclusion on this
>> a few months ago on this list, but we ended in an unresolved place. I'll try
>> again...
>>
>> Anyway, in this incarnation: the rule is that the return type must be a type
>> that includes instances of the current class. So, in class Point, QPoint is
>> okay, LObject is okay, but LString is not.
>
> I don't understand the point of this restriction. Since
> Ljava/lang/Object; is acceptable (and has to be), I can use a `<new>`
> method to return *any* class but the caller will need to downcast to
> use it.
I think the reason we might have some sort of restriction is if we intend for a
language or reflection API to be able to rely on these methods having some
consistent properties (imagine them being surfaced with
java.lang.reflect.Constructor, for example). So think of the restriction as a
placeholder ("we may have some sort of restriction on the return type, TBD").
We still need to do some work to figure out the precise requirements, if any.
