On Tuesday, 6 October 2020 at 18:24:14 UTC, Alaindevos wrote:
There are two subtractions possible.
A machine-one which can be architecture dependent, does not
have the same results on all computers, and behaves like a
modulus in mathematics.
A logical one. For the last one higher classes might be needed.
The (signed and unsigned) integer wrap around is well-defined in
D, and is architecture independent. That means for example that
if a specific architecture does not have a subtract instruction
that wraps around according to what D specifies, then the
compiler will generate the necessary instructions such that still
int.min - 1 == int.max. That's similar to how integer
multiplication 'just works' on architectures that do not have a
multiply instruction.
-Johan
