https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101029
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Jason Merrill <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:d92613ec5529cecd66ef0c21b894c7f70ace7f87 commit r11-8582-gd92613ec5529cecd66ef0c21b894c7f70ace7f87 Author: Jason Merrill <ja...@redhat.com> Date: Fri Jun 11 16:55:30 2021 -0400 c++: constexpr and array[0] [PR101029] build_vec_init_elt exits early if we're initializing a zero-element array, so build_vec_init needs to do the same to avoid trying to instantiate things after we've already started throwing important bits away. PR c++/101029 gcc/cp/ChangeLog: * init.c (build_vec_init): Shortcut [0] case. gcc/testsuite/ChangeLog: * g++.dg/ext/array4.C: New test.