On Thu, 28 May 2026 at 07:22, Tomasz Kaminski <[email protected]> wrote:
>
>
>
> On Wed, May 27, 2026 at 6:23 PM Patrick Palka <[email protected]> wrote:
>>
>> Changes in v2:
>>
>> - Bump FTM as per the paper
>> - Fix invariant preservation of flat_meow::swap in case of exception
>> - Use ranges::swap instead of ADL swap in flat_set::swap
>> - Make flat_meow::swap swap the comparator last
>> - Add missing flat_set::insert_range(sorted_foo_t, Rg&&) overload
>> - Clean up test, check .empty() alongside .keys().empty() and
>> .values.empty(), and don't bother doing .extract().
>>
>> -- >8 --
>>
>> This implements the changes in sections 5, 6 and 8 of P3567R2; the
>> changes in section 4 and 7 are already effectively implemented.
>>
>> libstdc++-v3/ChangeLog:
>>
>> * include/bits/version.def (flat_map): Bump to 202511.
>> (flat_set): Likewise.
>> * include/bits/version.h: Regenerate.
>> * include/std/flat_map (_Flat_map_impl): Remove
>> is_nothrow_swappable_v assertions.
>> (_Flat_map_impl::_Flat_map_impl): Explicitly default copy ctor.
>> Define move ctor with corrected exception handling as per
>> P3567R2.
>> (_Flat_map_impl::operator=): Likewise.
>> (_Flat_map_impl::insert_range): Define new __sorted_t overload
>> as per P3567R2.
>> (_Flat_map_impl::swap): Make conditionally noexcept as per
>> P3567R2.
>> * include/std/flat_set (_Flat_set_impl): Remove
>> is_nothrow_swappable_v assertion.
>> (_Flat_set_impl::_Flat_set_impl): Explicitly default copy ctor.
>> Define move ctor with correct invariant preserving behavior as
>> per P3567R2.
>> (_Flat_set_impl::operator=): Likewise.
>> (_Flat_set_impl::_M_insert_range): Factored out from
>> insert_range. Add bool parameter __is_sorted defaulted to
>> false.
>> (_Flat_set_impl::insert_range): Define new __sorted_t overload
>> as per P3567R2.
>> (_Flat_set_impl::swap): Make conditionally noexcept as per
>> P3567R2. Correct to use ranges::swap instead of ADL swap.
>> * libstdc++-v3/testsuite/23_containers/flat_map/1.cc
>> (test11, test12): New tests.
>> * libstdc++-v3/testsuite/23_containers/flat_multimap/1.cc
>> (test10, test11): New tests.
>> * libstdc++-v3/testsuite/23_containers/flat_multiset/1.cc
>> (test10, test11): New tests.
>> * libstdc++-v3/testsuite/23_containers/flat_set/1.cc
>> (test10, test11): New tests.
>> ---
>> libstdc++-v3/include/bits/version.def | 4 +-
>> libstdc++-v3/include/bits/version.h | 8 +-
>> libstdc++-v3/include/std/flat_map | 55 +++++++++-
>> libstdc++-v3/include/std/flat_set | 70 ++++++++++--
>> .../testsuite/23_containers/flat_map/1.cc | 103 +++++++++++++++++-
>> .../23_containers/flat_multimap/1.cc | 101 +++++++++++++++++
>> .../23_containers/flat_multiset/1.cc | 94 ++++++++++++++++
>> .../testsuite/23_containers/flat_set/1.cc | 96 +++++++++++++++-
>> 8 files changed, 508 insertions(+), 23 deletions(-)
>>
>> diff --git a/libstdc++-v3/include/bits/version.def
>> b/libstdc++-v3/include/bits/version.def
>> index 2f32a8bda98f..5d795151ec67 100644
>> --- a/libstdc++-v3/include/bits/version.def
>> +++ b/libstdc++-v3/include/bits/version.def
>> @@ -1899,7 +1899,7 @@ ftms = {
>> ftms = {
>> name = flat_map;
>
> The changes look good to me, with only small suggestion below.
>
> Could you add comments with paper numbers to FTMs, like we have
> in other cases:
> // 202207 P0429R9 A Standard flat_map
> // 202511 P3567R2 flat_meow Fixes
Yes please
>>
>> values = {
>
> v = 202207;
>>
>> + v = 202511; // P3567R2 applied as DR for C++23
>> cxxmin = 23;
>> };
>> };
>> @@ -1907,7 +1907,7 @@ ftms = {
>> ftms = {
>
> Similary here:
> // 202207 P1222R4 A Standard flat_set
> // LWG3751 Missing feature macro for flat_set
> // 202511 P3567R2 flat_meow Fixes
>>
>> name = flat_set;
>> values = {
>> - v = 202207;
>> + v = 202511;
>> cxxmin = 23;
>> };
>> };
