[External] : Re: Can not call a private method, no idea why ?

[Maurizio Cimadamore]

Some further history - this was tweaked several years ago in 7:

https://bugs.java.com/bugdatabase/view_bug.do?bug_id=6246814

There's also an open RFE on the spec:

https://bugs.openjdk.java.net/browse/JDK-6644562

Which basically refers to what we have discussed - e.g. the type system 
rules being too conservative and applying intersection type semantics 
even if there's only one bound.

Maurizio


On 21/01/2021 13:03, Maurizio Cimadamore wrote:
> I sympathize with your argument: at the end of the day, when you have 
> X <: Foo, you can always widen (e.g. assign) X to Foo (w/o warnings) 
> and take it from there, and all restrictions are gone - so maybe this 
> is excessive hand-holding on the language-side - but I was trying to 
> explain the rationale behind the rules - it is pretty common when 
> dealing with parametric polymorphism to think of membership of a 
> type-variable X in a "for all" semantics - e.g. the intersection of 
> members that are available in all instantiations of X; so, for the 
> language (and the compiler) X <: Foo and Foo are two very different 
> types, with very different membership rules.