Remove dups from array by key

remove_dups_from_array_by_key.rb

Hash[*a.map{|x| [x.text, x]}].values

a = [Thing.new('a'), Thing.new('b'), Thing.new('c'), Thing.new('c')]
# => [#<Thing a>, #<Thing b>, #<Thing c>, #<Thing c>]

Hash[a.map{|x| [x.text, x]}].values
# => [#<Thing a>, #<Thing b>, #<Thing c>]

class Thing
  attr_reader :text
  def initialize(text)
    @text = text
  end

  def inspect
    "#<Thing #{text}>"
  end
end