why does max_by_key with i32.log10() causing "attempt to add with overflow"

Question

I'm trying to get the max number of digits in an i32 array. I'm using log10(n) + 1 as my formula to calculate how many digits an i32 has and I thought I would just be able to use that within a max_by_key, but I am getting

thread 'main' panicked at 'attempt to add with overflow', /mnt/f/Personal-Docs/Repos/radix_sort_rs/src/lib/lib.rs:9:60
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Here's my code:

fn get_max_digits<const N: usize>(arr: [i32; N]) -> i32 {
    return *arr.iter().max_by_key(|a| a.log10() + 1).unwrap();
}

I'm still new to rust so sorry if this is a simple question.

Answer 1

Figured out the answer to my question not too long after posting. I was trying to do a logarithm of 0 causing undefined. I believe the attempt to add with overflow is the current interaction with 0i32.log10() as it is a nightly only feature.