RFR: [type-classes] Initial work to enable type-classes mediated operator support [v2]

[Chen Liang]

On Sun, 25 Jan 2026 22:15:04 GMT, Sylv <duke at openjdk.org> wrote:

> Why `__witness`? Why can't it be an annotation like `@Witness` or even `@OperatorOverload`?

I think the use of a keyword over annotation signifies the semantic impact of such a declaration.

> Also, why an anonymous class???

This is a freedom of implementation, the witness just wants an object. And anonymous class is usually the fastest way to create an object out of an interface. You can use other class declarations or lambda expressions too if the grammar allows.

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PR Comment: https://git.openjdk.org/valhalla/pull/1948#issuecomment-3797594516