How to split a string into only two parts, by the last occurrence of the split char?

String#rpartition, e.g.

irb(main):068:0> str = "Angry Birds 2.4.1"
=> "Angry Birds 2.4.1"
irb(main):069:0> str.rpartition(' ')
=> ["Angry Birds", " ", "2.4.1"]

Since the returned value is an array, using .first and .last would allow to treat the result as if it was split in two, e.g

irb(main):073:0> str.rpartition(' ').first
=> "Angry Birds"
irb(main):074:0> str.rpartition(' ').last
=> "2.4.1"

Something like this maybe ? Split where a space is followed by anything but a space till the end of the string.

"Angry Birds 2.4.1".split(/ (?=\S+$)/)
#=> ["Angry Birds", "2.4.1"]

I hava a solution like this:

class String
  def split_by_last(char=" ")
    pos = self.rindex(char)
    pos != nil ? [self[0...pos], self[pos+1..-1]] : [self]
  end
end

"Angry Birds 2.4.1".split_by_last  #=> ["Angry Birds", "2.4.1"]
"test".split_by_last               #=> ["test"]