How to check for overflow when adding/multiplying numbers?

[Dave P.]

On Monday, 6 December 2021 at 18:38:37 UTC, Ola Fosheim Grøstad 
wrote:
> On Monday, 6 December 2021 at 17:46:35 UTC, Dave P. wrote:
>> I’m porting some C code which uses the gcc intrinsics to do a 
>> multiply/add with overflow checking. See 
>> [here](https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html) for reference. Is there a D equivalent?
>
> There is:
>
> https://dlang.org/phobos/core_checkedint.html
>
> I have never used it, so I don't know how well it performs.

That seems to fit the bill.

Thanks!