On Thu, 6 Mar 2025 at 20:13, Jonathan Wakely wrote: > > The r15-2326-gea435261ad58ea change missed a static_assert for > is_move_constructible_v in expected<cv void, E>::value()&&. When > exceptions are enabled, the program is ill-formed if the error type is > not move constructible, because we can't construct the > std::bad_expected_access. But when using -fno-exceptions, we never > construct an exception, so don't need to copy/move the error value. So > that the same code compiles with/without exceptions enabled, we should > enforce the requirement explicitly. > > Add the static_assert, and a test that verifies the Mandates: > conditions added by LWG 3843 and 3490 are enforced even with > -fno-exceptions. > > libstdc++-v3/ChangeLog: > > * include/std/expected (expected<cv void,E>::value()&&): > Add missing static_assert for LWG 3940. > * testsuite/20_util/expected/lwg3843.cc: New test. > --- > > Tested x86_64-linux.
Also available for review at https://forge.sourceware.org/gcc/gcc-TEST/pulls/37
