+2024-03-12 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2024-03-07 Jonathan Wakely <jwakely@redhat.com>
+
+ * include/std/chrono (__get_leap_second_info): Update expiry
+ time for hardcoded list of leap seconds.
+ * testsuite/std/time/tzdb/leap_seconds.cc: Update comment.
+
+2024-03-12 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2024-02-29 Jonathan Wakely <jwakely@redhat.com>
+
+ * include/std/format (basic_format_arg::handle::__maybe_const_t):
+ Fix condition to check if const type is formattable.
+ (basic_format_arg::handle::handle(T&)): Remove redundant
+ static_assert.
+ * testsuite/std/format/formatter/basic.cc: New test.
+
+2024-03-12 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2024-01-08 Jonathan Wakely <jwakely@redhat.com>
+
+ * include/bits/chrono_io.h (__formatter_chrono): Always use
+ lvalue arguments to make_format_args.
+ * include/std/format (make_format_args): Change parameter pack
+ from forwarding references to lvalue references. Remove use of
+ remove_reference_t which is now unnecessary.
+ (format_to, formatted_size): Remove incorrect forwarding of
+ arguments.
+ * testsuite/20_util/duration/io.cc: Use lvalues as arguments to
+ make_format_args.
+ * testsuite/std/format/arguments/args.cc: Likewise.
+ * testsuite/std/format/arguments/lwg3810.cc: Likewise.
+ * testsuite/std/format/functions/format.cc: Likewise.
+ * testsuite/std/format/functions/vformat_to.cc: Likewise.
+ * testsuite/std/format/string.cc: Likewise.
+ * testsuite/std/time/day/io.cc: Likewise.
+ * testsuite/std/time/month/io.cc: Likewise.
+ * testsuite/std/time/weekday/io.cc: Likewise.
+ * testsuite/std/time/year/io.cc: Likewise.
+ * testsuite/std/time/year_month_day/io.cc: Likewise.
+ * testsuite/std/format/arguments/args_neg.cc: New test.
+
+2024-03-12 Cassio Neri <cassio.neri@gmail.com>
+
+ Backported from master:
+ 2024-01-05 Cassio Neri <cassio.neri@gmail.com>
+
+ * include/std/chrono: Fix + and - for months and weekdays.
+ * testsuite/std/time/month/1.cc: Add constexpr tests against overflow.
+ * testsuite/std/time/month/2.cc: New test for extreme values.
+ * testsuite/std/time/weekday/1.cc: Add constexpr tests against overflow.
+ * testsuite/std/time/weekday/2.cc: New test for extreme values.
+
+2024-03-12 Cassio Neri <cassio.neri@gmail.com>
+
+ Backported from master:
+ 2023-11-14 Cassio Neri <cassio.neri@gmail.com>
+
+ * include/std/chrono (operator-(const weekday&, const weekday&)):
+ Optimize.
+
+2024-03-12 Cassio Neri <cassio.neri@gmail.com>
+
+ Backported from master:
+ 2023-11-14 Cassio Neri <cassio.neri@gmail.com>
+
+ * include/std/chrono (year::is_leap): Clear code.
+
+2024-03-12 Cassio Neri <cassio.neri@gmail.com>
+
+ Backported from master:
+ 2023-11-14 Cassio Neri <cassio.neri@gmail.com>
+
+ * include/std/chrono (year_month_day_last::day): Remove &1.
+
+2024-03-12 Cassio Neri <cassio.neri@gmail.com>
+
+ Backported from master:
+ 2023-11-14 Cassio Neri <cassio.neri@gmail.com>
+
+ * include/std/chrono (weekday::_S_from_days): Fix UB.
+ * testsuite/std/time/weekday/1.cc: Add test for overflow.
+
+2024-03-12 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2023-11-11 Jonathan Wakely <jwakely@redhat.com>
+
+ * include/std/span (span, as_bytes, as_writable_bytes): Add
+ [[nodiscard]] attribute on all non-void functions.
+ * testsuite/23_containers/span/back_assert_neg.cc: Suppress
+ nodiscard warning.
+ * testsuite/23_containers/span/back_neg.cc: Likewise.
+ * testsuite/23_containers/span/first_2_assert_neg.cc: Likewise.
+ * testsuite/23_containers/span/first_assert_neg.cc: Likewise.
+ * testsuite/23_containers/span/first_neg.cc: Likewise.
+ * testsuite/23_containers/span/front_assert_neg.cc: Likewise.
+ * testsuite/23_containers/span/front_neg.cc: Likewise.
+ * testsuite/23_containers/span/index_op_assert_neg.cc: Likewise.
+ * testsuite/23_containers/span/index_op_neg.cc: Likewise.
+ * testsuite/23_containers/span/last_2_assert_neg.cc: Likewise.
+ * testsuite/23_containers/span/last_assert_neg.cc: Likewise.
+ * testsuite/23_containers/span/last_neg.cc: Likewise.
+ * testsuite/23_containers/span/subspan_2_assert_neg.cc:
+ Likewise.
+ * testsuite/23_containers/span/subspan_3_assert_neg.cc:
+ Likewise.
+ * testsuite/23_containers/span/subspan_4_assert_neg.cc:
+ Likewise.
+ * testsuite/23_containers/span/subspan_5_assert_neg.cc:
+ Likewise.
+ * testsuite/23_containers/span/subspan_6_assert_neg.cc:
+ Likewise.
+ * testsuite/23_containers/span/subspan_assert_neg.cc: Likewise.
+ * testsuite/23_containers/span/subspan_neg.cc: Likewise.
+ * testsuite/23_containers/span/nodiscard.cc: New test.
+
+2024-03-12 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2023-08-09 Jonathan Wakely <jwakely@redhat.com>
+
+ * include/bits/list.tcc (list::sort(Cmp)): Fix -Wsign-compare
+ warning for loop condition.
+
+2024-03-12 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2023-06-09 Jonathan Wakely <jwakely@redhat.com>
+
+ PR libstdc++/110167
+ * include/std/array (to_array): Initialize arrays of trivial
+ types using memcpy. For non-trivial types, use lambda
+ expressions instead of a separate helper function.
+ (__to_array): Remove.
+ * testsuite/23_containers/array/creation/110167.cc: New test.
+
2024-03-01 Jonathan Wakely <jwakely@redhat.com>
Backported from master: