[OT] The Usual Arithmetic Confusions

[Nick Treleaven]

On Saturday, 29 January 2022 at 12:23:28 UTC, Siarhei Siamashka 
wrote:
> So that `a[i % a.length]` has no performance disadvantages 
> compared to `a[i]`. My guess is that the D language design in 
> this alternative reality would define arrays indexing as a 
> modular operation and consider the "memory safety" goal 
> perfectly achieved (no out of bounds accesses, yay!). Ignoring 
> the fact that landing on a wrong array index is a source of all 
> kind of hard to debug problems, leading to wrong computations 
> or even security vulnerabilities.

I doubt that. There are many things in the design of D and Phobos 
that prevent bugs that aren't related to memory safety, sometimes 
even at the expense of efficiency. E.g. initializing integers by 
default is not necessary for @safe, even though in certain 
unoptimizable cases initialization is unnecessary and slower. 
Override the default when necessary. As with bound checks by 
default, this is the best design.