Should I choose Ada, SPARK, or Rust over C/C++? (2024) • Hacker News Board

Re: Should I choose Ada, SPARK, or Rust over C/C++? (2024)

#171

Post by uecker » Thu, Oct 09, 2025, 4:02 PM UTC

1718627440 wrote: post #165

uecker wrote: post #149

Earlier quoted context omitted.

Indeed, this is what many people do. But even if you use dynamic memory, if you replace pointer arithmetic by array indexing, you get bounds checking. And in C this also works for arrays of run-time length.

But can't I put any pointer arithmetic in array brackets, so it wouldn't limit anything?

Whatever index you compute can be checked against a bound.

Re: Should I choose Ada, SPARK, or Rust over C/C++? (2024)

#172

Post by 1718627440 » Fri, Oct 10, 2025, 5:41 PM UTC

uecker wrote: post #171

1718627440 wrote: post #165

Earlier quoted context omitted.

But can't I put any pointer arithmetic in array brackets, so it wouldn't limit anything?

Whatever index you compute can be checked against a bound.

2[a*b] What bound?

Re: Should I choose Ada, SPARK, or Rust over C/C++? (2024)

#173

Post by uecker » Sat, Oct 11, 2025, 9:42 AM UTC

1718627440 wrote: post #172

uecker wrote: post #171

Earlier quoted context omitted.

Whatever index you compute can be checked against a bound.

2[a*b] What bound?

This does not even compile. For array indexing,

array[expression]

if "array" has a bound whatever expression evaluates to can be checked against the bound of array. If "array" is not a bounded array but a pointer or an unbounded array, then this does not work, but my point is that it is easy to avoid such code.