On 10/16/2019 02:34 PM, Dennis wrote:
> Except that e.g. -2 - int.max underflows to int.max suggesting that
> int.max < -2.
Timon had corrected me on that point a while back, so I had added the
following warning at
http://ddili.org/ders/d.en/operator_overloading.html#ix_operator_overloading.opCmp
"Warning: Using subtraction for the implementation of opCmp is a bug if
valid values of a member can cause overflow."
However, note how I say "overflow" instead of "underflow". The reason
is, underflow is a different concept that applies only to floating point
values[1]. Apparently, "integer underflow" has become common usage as
well[2].
Ali
[1] https://en.wikipedia.org/wiki/Arithmetic_underflow
[2] https://en.wikipedia.org/wiki/Integer_overflow
