On Wednesday, 16 July 2014 at 21:26:41 UTC, Gary Willoughby wrote:
This was asked a few years ago and i could find a definitive
answer.
http://forum.dlang.org/thread/[email protected]
On Saturday, 5 May 2012 at 04:57:48 UTC, Alex Rønne Petersen
wrote:
I don't think the language really makes it clear whether
overflows and underflows are well-defined. Do we guarantee
that for any integral type T, T.max + 1 == T.min and T.min - 1
== T.max?
What is the current situation of integer overflow and underflow?
My understanding:
Every machine D will feasibly support will do T.max + 1 == T.min
and T.min - 1 == T.max for native integral operations, signed or
unsigned.
BUT:
We are using C(++) backends, which may assumed an undefined
result for signed over/underflow. Optimisers could cause us pain
here.
BUT:
It's probably not taken advantage of due to the amount of C code
that assumes the expected semantics. Also, there may be ways of
telling backends that it is defined and we may be using those
ways, I don't know.
