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Subject: Re: [SG16-Unicode] Hidden locale dependency in [time.duration.io]?
From: Tom Honermann (tom_at_[hidden])
Date: 2019-11-04 02:45:00


On 11/4/19 7:18 AM, Howard Hinnant wrote:
> On Nov 4, 2019, at 12:27 AM, Tom Honermann <tom_at_[hidden]> wrote:
>> I suggest the following wording: (using terminology from P1859R0)
>>
>> If Period::type is micro, but the character U+00B5 <del>cannot be represented in the encoding used</del><ins>lacks representation in the execution character set</ins> for charT, the unit suffix "us" is used instead of "μs". <ins>If
>> "μs" is used but the dynamic encoding lacks representation for U+00B5 and the stream is associated with a terminal or console, or if the stream is imbued with a std::codecvt facet that lacks conversion support for the character, then the result is unspecified.</ins>
>>
> I've no objection to an issue, but your proposed wording explicitly involves two things I'm strongly against:
>
> 1. Now the code has to check the locale, for this precision only.
>
> 2. Now the code has different behavior between cout and ostringstream. And the result of ostringstream is very commonly subsequently sent to cout (ostringstream is a common formatting aid).
>
> Imo, the proposed wording is much, much worse than the status-quo and I would vote strongly against it.

No, the wording I proposed doesn't check for locale.  The execution
character set is the character set used for string literals and is known
at compile time; it is not the locale dependent run-time character set.

Tom.

>
> Howard
>
>


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