https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92427
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> --- GCC 5 says: 92427.C:11:25: error: too many initializers for ‘C [0]’ } y = { 1, { { 2, 3 } } }; ^ then since r231665 we accepted the test. Then since r233126 92427.C: In destructor ‘y::~y()’: 92427.C:9:8: error: unknown array size in delete struct y { ^ 92427.C: In function ‘void __static_initialization_and_destruction_0(int, int)’: 92427.C:11:3: note: synthesized method ‘y::~y()’ first required here } y = { 1, { { 2, 3 } } }; ^ And the ICE started with r233183.