This summarizes GCC 11's change in build requirements from C++98 to C++11, for the release notes. I've put it in the Caveats immediately below the "The default mode for C++ is..." change hence the wording.
I've based it on the change to gcc/doc/install.texi in the GCC source tree, which was 5329b59a2e13dabbe2038af0fe2e3cf5fc7f98ed there. Validates. OK to commit? --- htdocs/gcc-11/changes.html | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/htdocs/gcc-11/changes.html b/htdocs/gcc-11/changes.html index e2a32e51..e33abe44 100644 --- a/htdocs/gcc-11/changes.html +++ b/htdocs/gcc-11/changes.html @@ -35,6 +35,11 @@ a work-in-progress.</p> features with <code>-fno-new-ttp-matching</code>. </li> + <li>When building GCC itself, the host compiler must now support C++11, + rather than C++98. In particular bootstrapping GCC 11 using an older + version of GCC requires a binary of GCC 4.8 or later, rather than of + GCC 3.4 or later as was the case for bootstrapping GCC 10.</li> + <li>Naming and location of auxiliary and dump output files changed. If you compile multiple input files in a single command, if you enable Link Time Optimization, or if you use <code>-dumpbase</code>, -- 2.26.2