From: "Eregon (Benoit Daloze) via ruby-core" <ruby-core@...>
Date: 2025-01-15T14:49:26+00:00
Subject: [ruby-core:120697] [Ruby master Bug#21040] String#next! method does not mutate $& variable

Issue #21040 has been updated by Eregon (Benoit Daloze).

Status changed from Open to Rejected

`$&` returns a new String on every usage, so this is fully expected:
```
$ ruby -e '"a" =~ /a/; p $&.object_id; p $&.object_id' 
60
80
```

----------------------------------------
Bug #21040: String#next! method does not mutate $& variable
https://bugs.ruby-lang.org/issues/21040#change-111532

* Author: radarek (Rados��aw Bu��at)
* Status: Rejected
* ruby -v: ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [arm64-darwin24]
* Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN
----------------------------------------
`String#next!` method should mutate string and return mutated version. For some reason, using it on `$&` does not mutate it but still returns new version.

Steps to reproduce (2 different ways):


```ruby
"123".gsub(/./){$&.next!}    # returns "234" as expected
"123".gsub(/./){$&.next!;$&} # returns "123" but should be "234"
"123".gsub(/./){_1.next!;_1} # returns "234" as expected



"123"[/./]
puts $&.      # prints 1
puts $&.next! # prints 2
puts $&       # prints 1 but should be 2
```




-- 
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