+2023-06-06 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2023-06-01 Jonathan Wakely <jwakely@redhat.com>
+
+ * include/std/expected (expected::and_then, expected::or_else)
+ (expected::transform_error): Use _M_val and _M_unex instead of
+ calling value() and error(), as per LWG 3938.
+ (expected::transform): Likewise. Remove incorrect std::move
+ calls from lvalue overloads.
+ (expected<void, E>::and_then, expected<void, E>::or_else)
+ (expected<void, E>::transform): Use _M_unex instead of calling
+ error().
+ * testsuite/20_util/expected/lwg3877.cc: Add checks for and_then
+ and transform, and for std::expected<void, E>.
+ * testsuite/20_util/expected/lwg3938.cc: New test.
+
+2023-06-06 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2023-05-17 Jonathan Wakely <jwakely@redhat.com>
+
+ * include/std/expected (expected::and_then, expected::or_else)
+ (expected::transform, expected::transform_error): Fix exception
+ specifications as per LWG 3877.
+ (expected<void, E>::and_then, expected<void, E>::transform):
+ Likewise.
+ * testsuite/20_util/expected/lwg3877.cc: New test.
+
+2023-06-06 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2023-06-06 Jonathan Wakely <jwakely@redhat.com>
+
+ PR libstdc++/108178
+ * src/filesystem/ops-common.h (do_copy_file): Check for empty
+ files by trying to read a character.
+ * testsuite/27_io/filesystem/operations/copy_file_108178.cc:
+ New test.
+
+2023-06-06 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2023-06-06 Jonathan Wakely <jwakely@redhat.com>
+
+ * src/filesystem/ops-common.h (do_copy_file) [O_CLOEXEC]: Set
+ close-on-exec flag on file descriptors.
+
+2023-06-06 Jonathan Wakely <jwakely@redhat.com>
+
+ Backported from master:
+ 2023-06-06 Jonathan Wakely <jwakely@redhat.com>
+
+ PR libstdc++/110139
+ * include/std/array (__array_traits<T, 0>::operator T*()): Make
+ conversion operator explicit.
+ (array::front): Use size_type as subscript operand.
+ (array::data): Use static_cast to make conversion explicit.
+ * testsuite/23_containers/array/element_access/110139.cc: New
+ test.
+
+2023-06-06 Joseph Faulls <Joseph.Faulls@imgtec.com>
+
+ Backported from master:
+ 2023-06-06 Joseph Faulls <Joseph.Faulls@imgtec.com>
+
+ * include/bits/locale_classes.tcc: Remove check for
+ codecvt<char8_t, char, mbstate_t> facet.
+
2023-06-01 Jonathan Wakely <jwakely@redhat.com>
Backported from master: