I'm including gcc@gcc.gnu.org here for visibility, but the discussion
really belongs on the libstdc++ list so please limit replies to there.
I'd like to discuss deprecating (and eventually removing) the
libstdc++-v3/include/ext/pb_ds extensions. For information on them see
https://gcc.gnu.org/onlinedocs/libstdc++/manual/policy_data_structures.html
There has been exactly one (1) bug report for them in the past seven
years since the code stabilized (i.e. when Benjamin stopped working on
them). The bug reporter and the author of the fix have both confirmed
they don't use them for anything "serious" that requires them to be
shipped as part of GCC (see PR 62045).
I can find no uses of them in https://codesearch.debian.net or
https://codesearch.isocpp.org/
They require occasional tweaking but many of the changes are just
touching comments. However, running the tests is very slow, see
https://gcc.gnu.org/ml/libstdc++/2019-03/msg00012.html
I'd like to consider deprecating them, and then removing them from the
libstdc++ tree. There's no reason the code can't be moved to a
separate project on sourceware.org (and/or gitlab, github etc.) but I
don't think it needs to be maintained as part of libstdc++.
