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From: Tim Rentsch
Newsgroups: comp.lang.c
Subject: Re: printf and time_t
Date: Sun, 11 Jan 2026 11:51:43 -0800
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Michael S writes:
> On Sat, 10 Jan 2026 22:02:03 -0500
> "James Russell Kuyper Jr." wrote:
>
>> On 2026-01-09 07:18, Michael S wrote:
>>
>>> On Thu, 8 Jan 2026 19:31:13 -0500
>>> "James Russell Kuyper Jr." wrote:
>>
>> ...
>>
>>>> I'd have no problem with your approach if you hadn't falsely
>>>> claimed that "It is correct on all platforms".
>>>
>>> Which I didn't.
>>
>> On 2026-01-07 19:38, Michael S wrote:
>> ...
>>
>>> No, it is correct on all implementation.
>>
>
> The quote is taken out of context.
> The context was that on platforms that have properties (a) and (b) (see
> below) printing variables declared as uint32_t via %u is probably UB
> according to the Standard (I don't know for sure, however it is
> probable), but it can't cause troubles with production C compiler. Or
> with any C compiler that is made in intention of being used rather than
> crafted to prove theoretical points.
> Properties are:
> a) uint32_t aliased to 'unsigned long'
> b) 'unsigned int' is at least 32-bit wide.
It seems unlikely that any implementation would make such a
choice. Can you name one that does?