Decimal.opEquals
bool opEquals(const typeof(this) rhs) const @safe pure nothrow @nogcNumerical equality: trailing zeros, ±0 and NaN per IEEE (NaN unequal to everything, including itself).
bool opEquals(const typeof(this) rhs) const @safe pure nothrow @nogcNumerical equality: trailing zeros, ±0 and NaN per IEEE (NaN unequal to everything, including itself).