dawn-cmake/test/shader_io/fragment_output_locations_struct.wgsl

struct FragmentOutputs {
  [[location(0)]] loc0 : i32;
  [[location(1)]] loc1 : u32;
  [[location(2)]] loc2 : f32;
  [[location(3)]] loc3 : vec4<f32>;
};

[[stage(fragment)]]
fn main() -> FragmentOutputs {
  return FragmentOutputs(1, 1u, 1.0, vec4<f32>(1.0, 2.0, 3.0, 4.0));
}