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Subject: Re: [SG16-Unicode] Hidden locale dependency in [time.duration.io]?
From: Howard Hinnant (howard.hinnant_at_[hidden])
Date: 2019-11-04 01:18:46


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.

Howard




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