class WEBrick::HTTPVersion

def self.convert(version)
  version.is_a?(self) ? version : new(version)
end

def <=>(other)
  unless other.is_a?(self.class)
    other = self.class.new(other)
  end
  if (ret = @major <=> other.major) == 0
    return @minor <=> other.minor
  end
  return ret
end

def initialize(version)
  case version
  when HTTPVersion
    @major, @minor = version.major, version.minor
  when String
    if /^(\d+)\.(\d+)$/ =~ version
      @major, @minor = $1.to_i, $2.to_i
    end
  end
  if @major.nil? || @minor.nil?
    raise ArgumentError,
      format("cannot convert %s into %s", version.class, self.class)
  end
end

def to_s
  format("%d.%d", @major, @minor)
end