On Mon, 22 Dec 2025 at 11:06, Tomasz Kamiński <[email protected]> wrote: > > The _GLIBCXX_USE_OLD_GENERATE_CANONICAL was introduced by > r16-6177-g866bc8a9214b1d that implemented P0952R2 [1] resolution > for LWG2524 as DR against C++20. > > The _GLIBCXX_USE_VARIANT_CXX17_OLD_ABI was introduced by > r16-6301-gb3c167b61fd75f that resovled PR112591. > > [1] https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p0952r2.html > > libstdc++-v3/ChangeLog: > > * doc/html/manual/using_macros.html: Regenerate. > * doc/xml/manual/using.xml: Add entries for > _GLIBCXX_USE_OLD_GENERATE_CANONICAL and > _GLIBCXX_USE_VARIANT_CXX17_OLD_ABI. > --- > OK for trunk? > > .../doc/html/manual/using_macros.html | 12 +++++++++++ > libstdc++-v3/doc/xml/manual/using.xml | 20 +++++++++++++++++++ > 2 files changed, 32 insertions(+) > > diff --git a/libstdc++-v3/doc/html/manual/using_macros.html > b/libstdc++-v3/doc/html/manual/using_macros.html > index c1406ec76f7..08649c1dfaa 100644 > --- a/libstdc++-v3/doc/html/manual/using_macros.html > +++ b/libstdc++-v3/doc/html/manual/using_macros.html > @@ -137,4 +137,16 @@ > When not defined, durations, time points, and calendar types are > available for freestanding, but the standard clocks and the time zone > database are not (because they require OS support). > + </p></dd><dt><span class="term"><code > class="code">_GLIBCXX_USE_OLD_GENERATE_CANONICAL</code></span></dt><dd><p> > + Undefined by default. When defined <code > class="code">generate_canonical</code> > + reverts to algorithm used by before implementation of > + <a class="link" > href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p0952r2.html"; > target="_top">P0952 > + A new specification for std::generate_canonical</a> in GCC-16. > + </p></dd><dt><span class="term"><code > class="code">_GLIBCXX_USE_VARIANT_CXX17_OLD_ABI</code></span></dt><dd><p> > + Undefined by default. When defined <code class="code">variant</code> > in C++17 > + mode will revert to non-conforming implementation used prior > + resolution of > + <a class="link" > href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112591"; > target="_top">PR112591</a> > + in GCC-16. > + Has no impact for C++20 or later modes. > </p></dd></dl></div></div><div class="navfooter"><hr /><table > width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a > accesskey="p" href="using_headers.html">Prev</a> </td><td width="20%" > align="center"><a accesskey="u" href="using.html">Up</a></td><td width="40%" > align="right"> <a accesskey="n" > href="using_dual_abi.html">Next</a></td></tr><tr><td width="40%" align="left" > valign="top">Headers </td><td width="20%" align="center"><a accesskey="h" > href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> > Dual ABI</td></tr></table></div></body></html> > \ No newline at end of file > diff --git a/libstdc++-v3/doc/xml/manual/using.xml > b/libstdc++-v3/doc/xml/manual/using.xml > index bec5419d587..0a9f9f6e46c 100644 > --- a/libstdc++-v3/doc/xml/manual/using.xml > +++ b/libstdc++-v3/doc/xml/manual/using.xml > @@ -1343,6 +1343,26 @@ g++ -Winvalid-pch -I. -include stdc++.h -H -g -O2 > hello.cc -o test.exe > database are not (because they require OS support). > </para> > </listitem></varlistentry> > + > <varlistentry><term><code>_GLIBCXX_USE_OLD_GENERATE_CANONICAL</code></term> > + <listitem> > + <para> > + Undefined by default. When defined <code>generate_canonical</code> > + reverts to algorithm used by before implementation of
"reverts to the algorithm used prior to the implementation of" > + <link xmlns:xlink="http://www.w3.org/1999/xlink"; > xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p0952r2.html";>P0952 > + A new specification for std::generate_canonical</link> in GCC-16. > + </para> > + </listitem></varlistentry> > + > <varlistentry><term><code>_GLIBCXX_USE_VARIANT_CXX17_OLD_ABI</code></term> > + <listitem> > + <para> > + Undefined by default. When defined <code>variant</code> in C++17 > + mode will revert to non-conforming implementation used prior "mode will revert to the non-conforming implementation used prior to the" OK with those two changes (and don't forget to regenerate the HTML). Thanks for updating the docs with this. > + resolution of > + <link xmlns:xlink="http://www.w3.org/1999/xlink"; > xlink:href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112591";>PR112591</link> > + in GCC-16. > + Has no impact for C++20 or later modes. > + </para> > + </listitem></varlistentry> > </variablelist> > > </section> > -- > 2.52.0 >
