On Wed, Nov 26, 2025 at 03:15:59PM +0100, Jakub Jelinek wrote:
> Hi!
>
> On Wed, Nov 26, 2025 at 07:23:43PM +0530, Jason Merrill wrote:
> > On 11/26/25 7:20 PM, Jakub Jelinek wrote:
> > > On Wed, Nov 26, 2025 at 08:45:49AM -0500, Marek Polacek wrote:
> > > > I think this should be @option{-fmodules}.
> > > >
> > > > > The name @samp{c++2a} is deprecated.
> > > > > @item gnu++20
> > > > > @itemx gnu++2a
> > > > > GNU dialect of @option{-std=c++20}.
> > > > > This is the default for C++ code.
> > > > > +C++20 modules support is still experimental and needs to be
> > > > > +enabled with @code{-fmodules} option.
> > > >
> > > > Ditto.
> > >
> > > Thanks, changed in my copy.
> >
> > OK with that adjustment.
>
> Thanks, now committed.
>
> What about wwwdocs?
>
> Something like this?
Seems fine. We're also going to have to update gcc-16/changes.html.
> diff --git a/htdocs/projects/cxx-status.html b/htdocs/projects/cxx-status.html
> index 838b318b..e97dbc15 100644
> --- a/htdocs/projects/cxx-status.html
> +++ b/htdocs/projects/cxx-status.html
> @@ -719,20 +719,20 @@
>
> <h2 id="cxx20">C++20 Support in GCC</h2>
>
> - <p id="cxx2a">GCC has experimental support for the previous revision of
> the C++
> - standard, which was published in 2020.
> + <p id="cxx2a">GCC has almost full support for the previous revision of the
> + C++ standard, which was published in 2020.
> The status of C++20 library features is described in
> <a
> href="https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.2020";>the
> library documentation</a>.</p>
>
> - <p>C++20 features are available since GCC 8. To enable C++20
> - support, add the command-line parameter <code>-std=c++20</code>
> - (use <code>-std=c++2a</code> in GCC 9 and earlier)
> - to your <code>g++</code> command line. Or, to enable GNU
> - extensions in addition to C++20 features,
> - add <code>-std=gnu++20</code>.</p>
> -
> - <p><strong>Important</strong>: Because the ISO C++20 standard is
> - recent, GCC's support is <strong>experimental</strong>.</p>
> + <p>C++20 mode is the default since GCC 16; it can be explicitly selected
> + with the <code>-std=c++20</code> command-line flag, or
> + <code>-std=gnu++20</code> to enable GNU extensions as well
> + (use <code>-std=c++2a</code> in GCC 9 and earlier).
> + Some C++20 features are available since GCC 8, but support was experimental
> + and the ABI of C++20 features was not stable until GCC 16.
> + C++20 modules support is still <strong>experimental</strong> and needs to
> be
> + enabled by <code>-fmodules</code> command-line flag.
> + </p>
>
> <h2>C++20 Language Features</h2>
>
> @@ -1309,8 +1309,8 @@
> <a
> href="https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.2017";>the
> library documentation</a>.
> </p>
>
> - <p>C++17 mode is the default since GCC 11; it can be explicitly selected
> - with the <code>-std=c++17</code> command-line flag, or
> + <p>This mode is the default in GCC 11 up until GCC 15 (inclusive); it can
> be
> + explicitly selected with the <code>-std=c++17</code> command-line flag, or
> <code>-std=gnu++17</code> to enable GNU extensions as well.
> Some C++17 features are available since GCC 5, but support was experimental
> and the ABI of C++17 features was not stable until GCC 9.
Marek
