assert 'Bigint basic' do
  n = 1<<65
  assert_equal 36893488147419103232, n
  assert_equal 36893488147419104229, n+997
  assert_equal 36893488147419102235, n-997
  assert_equal 36782807682976845922304, n*997
  assert_equal 37004501652376231, n.div(997)
end

assert 'Bigint to_s' do
  n = 1197857166996989179607278372168909873645893814254642585755536286462800958278984531968
  assert_equal n, "11978_571669_96989179607278372168909873645893814254642585755536286462800958278984531968".to_i
  assert_equal(-n, "-11978_571669_96989179607278372168909873645893814254642585755536286462800958278984531968".to_i)
  n = 0x1197857166996989179607278372168909873645893814254642585755536286462800958278984531968
  assert_equal n, "1197857166996989179607278372168909873645893814254642585755536286462800958278984531968".to_i(16)
end

assert 'Bigint pow' do
  n = 18446744073709551616
  assert_equal n, 2 ** 64
  assert_equal n, 1 << 64
  assert_equal 2, n >> 63
end