RFR: 8356995: Provide default methods min(T, T) and max(T, T) in Comparator interface [v7]

[Tagir F. Valeev]

On Thu, 7 Aug 2025 21:05:13 GMT, Stuart Marks <smarks at openjdk.org> wrote:

>> Tagir F. Valeev has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Add @implSpec
>
> Intuitively, it feels to me like the invariant `min(a, b) == max(b, a)` would be useful when `a` and `b` compare equal. Still mulling this over....
> 
> EDIT: never mind. I can't think of a good reason to change the return-first-if-equal rule currently expressed in the spec.

@stuart-marks thank you for the review!
@liach I don't think it's an issue. Yes, it's possible to do the following:

  void test(Comparator<Object> cmp) {
    String a = "abc";
    StringBuilder b = new StringBuilder("abc");
    CharSequence max = cmp.max(a, b); // T = Object, U = CharSequence
  }

However, saying that "`CharSequence` is the type of `a` and `b`" is not incorrect. If we have an object of type `String`, it's also an object of type `CharSequence`.

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PR Comment: https://git.openjdk.org/jdk/pull/25297#issuecomment-3310950943