extern void abort (void); struct T { int t; int r[8]; }; struct S { int a; int b; int c[6]; struct T d; }; __attribute__((noinline)) void foo (struct S *s) { *s = (struct S) { s->b, s->a, { 0, 0, 0, 0, 0, 0 }, s->d }; } int main (void) { struct S s = { 6, 12, { 1, 2, 3, 4, 5, 6 }, { 7, { 8, 9, 10, 11, 12, 13, 14, 15 } } }; foo (&s); if (s.a != 12 || s.b != 6 || s.c[0] || s.c[1] || s.c[2] || s.c[3] || s.c[4] || s.c[5]) abort (); if (s.d.t != 7 || s.d.r[0] != 8 || s.d.r[1] != 9 || s.d.r[2] != 10 || s.d.r[3] != 11 || s.d.r[4] != 12 || s.d.r[5] != 13 || s.d.r[6] != 14 || s.d.r[7] != 15) abort (); return 0; }