Issue #19134 has been updated by Eregon (Benoit Daloze).
shugo (Shugo Maeda) wrote in #note-8:
`&` is allowed in 3.1, so it's a breaking
change to prohibit it.
Right and `&` is not problematic re performance, it's a completely separate
argument anyway.
I agree with your proposal in your comment just above this one.
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Feature #19134: ** is not allowed in def foo(...)
https://bugs.ruby-lang.org/issues/19134#change-100573
* Author: shugo (Shugo Maeda)
* Status: Open
* Priority: Normal
* Assignee: matz (Yukihiro Matsumoto)
* Target version: 3.2
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`*` and `&` are allowed in the body of a method with `...` argument forwarding, but
`**` is not allowed.
```
def foo(...)
bar(*) # OK
baz(&) # OK
quux(**) # NG
end
```
Is it intended behavior?
It seems that parse.y has code like `#ifdef RUBY3_KEYWORDS`, and if RUBY3_KEYWORDS, `**`
will also be supported.
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