https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97904
--- Comment #3 from Alex Coplan <acoplan at gcc dot gnu.org> --- FWIW, clang (trunk) rejects that last testcase with: <source>:3:6: error: array has sizeless element type '__SVFloat32_t' b x[c]; ^ <source>:6:19: note: in instantiation of template class 'a<__SVFloat32_t, 2>' requested here a<svfloat32_t, 2> x;