Issue #17785 has been updated by zverok (Victor Shepelev).


We actually can:
```ruby
def check(arg, class:)
  arg.is_a?(binding.local_variable_get('class'))
end
```
[Here](https://bugs.ruby-lang.org/issues/15647#change-77000) @nobu have argued that this is exactly how it is intended to be done.

I vaguely remember arguing somewhere about some syntax to access "specially named" local vars, but I don't remember what I've proposed then, and can't find the ticket :shrug:

----------------------------------------
Feature #17785: Allow named parameters to be keywords
https://bugs.ruby-lang.org/issues/17785#change-91393

* Author: marcandre (Marc-Andre Lafortune)
* Status: Open
* Priority: Normal
* Assignee: matz (Yukihiro Matsumoto)
----------------------------------------
We should allow named parameters to be keywords and use add a trailing `_` to the corresponding variable:

```ruby
def check(arg, class:)
  arg.is_a?(class_)
end

check(42, class: Integer) # => true
```

Currently, if we want such an API we have to use `**rest`:

```ruby
def check(arg, **rest)
  class_ = rest.fetch(:class) { raise ArgumentError('missing keyword: :class')}
  if rest.size > 1
    unknown = rest.keys - [:class]
    raise ArgumentError("unknown keyword(s): :#{unknown.join(', :')})
  end

  arg.is_a?(class_)
end
```

This is very verbose, much less convenient, much less readable, prevents `steep` from generating the proper signature, etc.

We should do the same for pattern match.



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