private BigDecimalMath() {}

  /**
   * 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},

  private BigDecimalMath() {}

  /**
   * 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},

        .setExpectation(Math.pow(2, 53), values())
        .test();
  }

  public void testRoundToDouble_maxPreciselyRepresentablePlusOne() {
    double twoToThe53 = Math.pow(2, 53);
    // the representable doubles are 2^53 and 2^53 + 2.
    // 2^53+1 is halfway between, so HALF_UP will go up and HALF_DOWN will go down.
    new RoundToDoubleTester(BigDecimal.valueOf((1L << 53) + 1))

import static com.google.common.math.MathPreconditions.checkRoundingUnnecessary;

import com.google.common.annotations.GwtIncompatible;
import java.math.RoundingMode;

/**
 * Helper type to implement rounding {@code X} to a representable {@code double} value according to
 * a {@link RoundingMode}.
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
abstract class ToDoubleRounder<X extends Number & Comparable<X>> {
  /**

import static com.google.common.math.MathPreconditions.checkRoundingUnnecessary;

import com.google.common.annotations.GwtIncompatible;
import java.math.RoundingMode;

/**
 * Helper type to implement rounding {@code X} to a representable {@code double} value according to
 * a {@link RoundingMode}.
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
abstract class ToDoubleRounder<X extends Number & Comparable<X>> {
  /**

  }

  /**
   * 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},

   * 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_EVEN}, this implementation uses the IEEE 754
   * default rounding mode: if the two nearest representable values are equally near, the one with

   * 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_EVEN}, this implementation uses the IEEE 754
   * default rounding mode: if the two nearest representable values are equally near, the one with

</li>
<li>
<code>x</code> is an untyped <a href="#Constants">constant</a>
<a href="#Representability">representable</a>
by a value of type <code>T</code>.
</li>
</ul>


<h3 id="Representability">Representability</h3>

<p>
A <a href="#Constants">constant</a> <code>x</code> is <i>representable</i>
by a value of type <code>T</code> if one of the following conditions applies:
</p>

<ul>

<a href="#Complex_numbers">components</a> <code>real(x)</code> and <code>imag(x)</code>
are representable by values of <code>T</code>'s component type (<code>float32</code> or
<code>float64</code>).
</li>
</ul>

<p>
If <code>T</code> is a type parameter,
<code>x</code> is representable by a value of type <code>T</code> if <code>x</code> is representable
by a value of each type in <code>T</code>'s type set.
</p>

<pre>