rails/rails — pull request #6392 by frodsan (2012-05-19 01:01:19+00:00)
Title: CollectionAssociation#empty? can take a block to define a criteria

Add:

```ruby
class Person < ActiveRecord::Base
has_many :pets
end

person.pets.size # => 2
person.pets.empty? # => false

# defining a criteria inside a block
person.pets.empty? do |pet|
pet.name.nil?
end
# => true
```

If it's accepted, i will update CollectionProxy#empty? documentation.