https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90532
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- Author: redi Date: Mon May 20 13:02:10 2019 New Revision: 271417 URL: https://gcc.gnu.org/viewcvs?rev=271417&root=gcc&view=rev Log: PR c++/90532 Ensure __is_constructible(T[]) is false An array of an unknown bound is an incomplete type, so no object of such a type can be constructed. This means __is_constructible should always be false for an array of unknown bound. This patch also changes the std::is_default_constructible trait to use std::is_constructible, which now gives the right answer for arrays of unknown bound. gcc/cp: Backported from mainline 2019-05-20 Jonathan Wakely <jwak...@redhat.com> PR c++/90532 Ensure __is_constructible(T[]) is false * method.c (is_xible_helper): Return error_mark_node for construction of an array of unknown bound. gcc/testsuite: Backported from mainline 2019-05-20 Jonathan Wakely <jwak...@redhat.com> PR c++/90532 Ensure __is_constructible(T[]) is false * g++.dg/ext/90532.C: New test. libstdc++-v3: Backported from mainline 2019-05-20 Jonathan Wakely <jwak...@redhat.com> PR c++/90532 Ensure __is_constructible(T[]) is false * include/std/type_traits (__do_is_default_constructible_impl) (__is_default_constructible_atom, __is_default_constructible_safe): Remove. (is_default_constructible): Use is_constructible. * testsuite/20_util/is_constructible/value.cc: Check int[] case. * testsuite/20_util/is_default_constructible/value.cc: Likewise. * testsuite/20_util/is_trivially_constructible/value.cc: Likewise. * testsuite/20_util/is_trivially_default_constructible/value.cc: Likewise. Added: branches/gcc-9-branch/gcc/testsuite/g++.dg/ext/90532.C Modified: branches/gcc-9-branch/gcc/cp/ChangeLog branches/gcc-9-branch/gcc/cp/method.c branches/gcc-9-branch/gcc/testsuite/ChangeLog branches/gcc-9-branch/libstdc++-v3/ChangeLog branches/gcc-9-branch/libstdc++-v3/include/std/type_traits branches/gcc-9-branch/libstdc++-v3/testsuite/20_util/is_constructible/value.cc branches/gcc-9-branch/libstdc++-v3/testsuite/20_util/is_default_constructible/value.cc branches/gcc-9-branch/libstdc++-v3/testsuite/20_util/is_trivially_constructible/value.cc branches/gcc-9-branch/libstdc++-v3/testsuite/20_util/is_trivially_default_constructible/value.cc
