https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117294
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- I'm seeing some libstdc++ regressions due to this (otherwise very nice) change, when the testsuite is run for C++20 and later: FAIL: 20_util/optional/cons/value_neg.cc -std=gnu++20 (test for excess errors) FAIL: 20_util/optional/cons/value_neg.cc -std=gnu++23 (test for excess errors) FAIL: 20_util/optional/cons/value_neg.cc -std=gnu++26 (test for excess errors) FAIL: 20_util/scoped_allocator/69293_neg.cc -std=gnu++20 (test for excess errors) FAIL: 20_util/scoped_allocator/69293_neg.cc -std=gnu++23 (test for excess errors) FAIL: 20_util/scoped_allocator/69293_neg.cc -std=gnu++26 (test for excess errors) FAIL: 20_util/variant/102912.cc -std=gnu++20 (test for excess errors) FAIL: 20_util/variant/102912.cc -std=gnu++23 (test for excess errors) FAIL: 20_util/variant/102912.cc -std=gnu++26 (test for excess errors) To run the tests in C++20 mode set GLIBCXX_TESTSUITE_STDS=20 in the env e.g. GLIBCXX_TESTSUITE_STDS=20 make check RUNTESTFLAGS=conformance.exp=20_util/optional/cons/value_neg.cc
