Function test_count_digits

test/format-impl-test.cc:248–255

// Tests fmt::detail::count_digits for integer type Int.
template <typename Int> void test_count_digits() {
  for (Int i = 0; i < 10; ++i) EXPECT_EQ(1u, fmt::detail::count_digits(i));
  for (Int i = 1, n = 1, end = max_value<Int>() / 10; n <= end; ++i) {
    n *= 10;
    EXPECT_EQ(fmt::detail::count_digits(n - 1), i);
    EXPECT_EQ(fmt::detail::count_digits(n), i + 1);
  }
}

TEST(format_impl_test, count_digits) {
  test_count_digits<uint32_t>();