class Shoulda::Matchers::ActiveModel::ValidateAcceptanceOfMatcher

def does_not_match?(subject)
  super(subject)
  allows_value_of(false, @expected_message)
end

def initialize(attribute)
  super
  @expected_message = :accepted
end

def matches?(subject)
  super(subject)
  disallows_value_of(false, @expected_message)
end

def simple_description
  %(validate that :#{@attribute} has been set to "1")
end