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From: Richard Kettlewell <invalid@invalid.invalid>
Newsgroups: comp.lang.c
Subject: Re: Hex string literals (was Re: C23 thoughts and opinions)
Date: Tue, 18 Jun 2024 16:14:38 +0100
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Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:
> Richard Kettlewell <invalid@invalid.invalid> writes:
>> There’s more to life than byte arrays, though, so I wonder if there’s
>> more to be said here. I find myself dealing a lot with large integers
>> generally represented as arrays of some unsigned type (commonly uint32_t
>> but other possibilities arise too).
>>
>> In C as it stands today this requires a translation step before
>> constants can be embedded in source code (which is error-prone if
>> someone attempts to do it manually).
>>
>> So being able to say ‘0x8732456872648956348596893765836543 as array of
>> uint64_t, LSW first’ (in some suitably C-like syntax) would be a big
>> improvement from my perspective, primarily as an accelerator to
>> development but also as a small improvement in robustness.
>
> You could use some kind of type punning.  For example, this is currently
> legal:
>
>     union {
>         unsigned char buf[4];
>         uint32_t n;
>     } obj = {
>         .buf = { 0x01, 0x02, 0x03, 0x04 }
>     };

I can’t use type punning if the data type is already set, which it often
is.

> The { 0x01, 0x02, 0x03, 0x04 } could be replaced with 0x"01020304".
>
> Of course you have to deal with endianness.

That’s a fatal problem for my use case.

-- 
https://www.greenend.org.uk/rjk/