Feature #17116
Updated by S_H_ (Shun Hiraoka) about 4 years ago
Now, `Enumerator#new` is allow this code(no given blocks).
```ruby
obj = Object.new
Enumerator.new(obj)
```
But, warning is displayed(since `ruby-2.0.0-preview2`).
```bash
-e:1: warning: Enumerator.new without a block is deprecated; use Object#to_enum instead
```
I think it's okay to remove this behaviour.
And I think that it seems natural to raise ArgumentError if no block given.
pull request:
https://github.com/ruby/ruby/pull/3408