struct S {
v : vec3<f32>;
};
[[group(0), binding(0)]] var<storage, read_write> U : S;
fn f() {
U.v = vec3<f32>(1.0, 2.0, 3.0);
U.v.x = 1.0;
U.v.y = 2.0;
U.v.z = 3.0;
}