#include struct T { int x; int y; struct T2 { int x; int y; } z; }; int main() { struct T t = {.y=2, {.x=3, 4, 5}}; assert(t.x == 0 && t.y == 2 && t.z.x == 3 && t.z.y == 5); return t.z.x; }