/** Returns d's value as an X, rounded with the specified mode. */
  abstract X toX(double d, RoundingMode mode);

  /** Returns a - b, guaranteed that both arguments are nonnegative. */
  abstract X minus(X a, X b);

  /** Rounds {@code x} to a {@code double}. */
  final double roundToDouble(X x, RoundingMode mode) {
    checkNotNull(x, "x");
    checkNotNull(mode, "mode");
    double roundArbitrarily = roundToDoubleArbitrarily(x);

    BigInteger x = BigInteger.TEN.pow(100);
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(100, BigIntegerMath.log10(x, mode));
    }
  }

  @GwtIncompatible // TODO
  public void testSqrtZeroAlwaysZero() {
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(ZERO, BigIntegerMath.sqrt(ZERO, mode));
    }
  }

  @GwtIncompatible // TODO

    BigInteger x = BigInteger.TEN.pow(100);
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(100, BigIntegerMath.log10(x, mode));
    }
  }

  @GwtIncompatible // TODO
  public void testSqrtZeroAlwaysZero() {
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(ZERO, BigIntegerMath.sqrt(ZERO, mode));
    }
  }

  @GwtIncompatible // TODO

  }

  /**
   * Returns {@code x}, rounded to a {@code double} with the specified rounding mode. If {@code x}
   * is precisely representable as a {@code double}, its {@code double} value will be returned;
   * otherwise, the rounding will choose between the two nearest representable values with {@code
   * mode}.
   *
   * <p>For the case of {@link RoundingMode#HALF_DOWN}, {@code HALF_UP}, and {@code HALF_EVEN},

    long x = 1000000000000L;
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(12, LongMath.log10(x, mode));
    }
  }

  @GwtIncompatible // TODO
  public void testSqrtNegativeAlwaysThrows() {
    for (long x : NEGATIVE_LONG_CANDIDATES) {
      for (RoundingMode mode : ALL_ROUNDING_MODES) {
        try {
          LongMath.sqrt(x, mode);
          fail("Expected IllegalArgumentException");

    long x = 1000000000000L;
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(12, LongMath.log10(x, mode));
    }
  }

  @GwtIncompatible // TODO
  public void testSqrtNegativeAlwaysThrows() {
    for (long x : NEGATIVE_LONG_CANDIDATES) {
      for (RoundingMode mode : ALL_ROUNDING_MODES) {
        try {
          LongMath.sqrt(x, mode);
          fail("Expected IllegalArgumentException");

            "spanNulls": false,
            "stacking": {
              "group": "A",
              "mode": "none"
            },
            "thresholdsStyle": {
              "mode": "off"
            }
          },
          "links": [],
          "mappings": [],
          "thresholds": {
            "mode": "absolute",
            "steps": [
              {
                "color": "green",

            "spanNulls": false,
            "stacking": {
              "group": "A",
              "mode": "none"
            },
            "thresholdsStyle": {
              "mode": "off"
            }
          },
          "mappings": [],
          "thresholds": {
            "mode": "absolute",
            "steps": [
              {
                "color": "green",
                "value": null

            "spanNulls": false,
            "stacking": {
              "group": "A",
              "mode": "none"
            },
            "thresholdsStyle": {
              "mode": "off"
            }
          },
          "mappings": [],
          "thresholds": {
            "mode": "absolute",
            "steps": [
              {
                "color": "green",

    int x = 1000000;
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(6, IntMath.log10(x, mode));
    }
  }

  // Simple test to cover sqrt(0) for all types and all modes.
  @GwtIncompatible // sqrt
  public void testSqrtZeroAlwaysZero() {
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(0, IntMath.sqrt(0, mode));
    }
  }

  @GwtIncompatible // sqrt