This only applies to legacy Windows APIs.

On Thu, Jul 2, 2026 at 8:48 PM Thiago Macieira via SG16 <
sg16_at_[hidden]> wrote:

> On Thursday, 2 July 2026 20:01:55 Pacific Daylight Time Victor Zverovich
> via
> SG16 wrote:
> > Moreover, ACP is mostly irrelevant in modern code and it's sufficient to
> > compile with /utf-8 on MSVC (and on most other systems UTF-8 is the
> default
> > for char).
>
> That's not correct. That causes the compiler to interpret the source input
> as
> UTF-8 and emit narrow character literals as UTF-8. It does not change how
> the
> narrow character APIs behave at runtime.
>
> To do that, you need to set the manifest flag that Tony mentioned. And
> only the
> application (a.k.a. the owner of main()) can do that. Library code cannot
> and
> must therefore cope with being run with another ACP. It could declare
> other
> ACPs are not supported, but that would limit the audience of the library,
> as
> most applications do not set the flag for some reason or another,
> including but
> not limited to simply not knowing about it.
>
> --
> Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
> Principal Engineer - Intel Data Center - Platform & Sys. Eng.
> --
> SG16 mailing list
> SG16_at_[hidden]
> https://lists.isocpp.org/mailman/listinfo.cgi/sg16
> Link to this post: http://lists.isocpp.org/sg16/2026/07/4780.php
>