// Converts a Decimal to a double. Since a double has fewer significant
// digits than a Decimal, this operation may produce round-off errors.
//
public static double ToDouble(Decimal d)
{
double result = 0.0;
// Note: this can fail if the input is an invalid decimal, but for compatibility we should return 0
DecCalc.VarR8FromDec(ref d, out result);
return(result);
}
// Returns the hash code for this Decimal.
//
public unsafe override int GetHashCode()
{
double dbl = DecCalc.VarR8FromDec(ref this);
if (dbl == 0.0)
{
// Ensure 0 and -0 have the same hash code
return(0);
}
// conversion to double is lossy and produces rounding errors so we mask off the lowest 4 bits
//
// For example these two numerically equal decimals with different internal representations produce
// slightly different results when converted to double:
//
// decimal a = new decimal(new int[] { 0x76969696, 0x2fdd49fa, 0x409783ff, 0x00160000 });
// => (decimal)1999021.176470588235294117647000000000 => (double)1999021.176470588
// decimal b = new decimal(new int[] { 0x3f0f0f0f, 0x1e62edcc, 0x06758d33, 0x00150000 });
// => (decimal)1999021.176470588235294117647000000000 => (double)1999021.1764705882
//
return((int)(((((uint *)&dbl)[0]) & 0xFFFFFFF0) ^ ((uint *)&dbl)[1]));
}
// Converts a Decimal to a double. Since a double has fewer significant
// digits than a Decimal, this operation may produce round-off errors.
//
public static double ToDouble(Decimal d)
{
return(DecCalc.VarR8FromDec(ref d));
}
