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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.arch
Subject: Re: Optimization by programmers
Date: Tue, 29 Sep 2026 15:44:56 -0700
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Michael S <already5chosen@yahoo.com> writes:

> On Mon, 28 Sep 2026 02:59:06 -0700
> Tim Rentsch <tr.17687@z991.linuxsc.com> wrote:
>
>> Terje Mathisen <terje.mathisen@tmsw.no> writes:
>>
>>> Tim Rentsch wrote:
[...]
>>>> I favor a type equivalent to size_t for use as array index
>>>> variables.
>>>
>>> In Rust, the only acceptable array index is of type "usize", which
>>> is effectively the same as u64 on most platforms these days, but
>>> does not need to be so:  On a 32-bit target, it would be the same
>>> as u32.
>>>
>>> So effectively very similar to size_t.
>>
>> Maybe that limitation works okay in Rust.  In C sometimes it's
>> important to allow a signed value for indexing.  Probably 99% of
>> the time size_t is good, but not always.
>
> My only Rust program was full of casts of various integer types to
> usize.  Exactly for the purpose of array indexing.

That tells me a lot.  Thank you.