SKIP: FAILED

#include <metal_stdlib>
using namespace metal;
template<typename T, size_t N>
struct tint_array {
  const constant T& operator[](size_t i) const constant { return elements[i]; }
  device T& operator[](size_t i) device { return elements[i]; }
  const device T& operator[](size_t i) const device { return elements[i]; }
  thread T& operator[](size_t i) thread { return elements[i]; }
  const thread T& operator[](size_t i) const thread { return elements[i]; }
  threadgroup T& operator[](size_t i) threadgroup { return elements[i]; }
  const threadgroup T& operator[](size_t i) const threadgroup { return elements[i]; }
  T elements[N];
};


vertex float4 vtx_main(uint VertexIndex [[]]) {
  return float4(tint_array<float2, 3>{float2(0.0f, 0.5f), float2(-0.5f), float2(0.5f, -0.5f)}[VertexIndex], 0.0f, 1.0f);
}
fragment float4 frag_main() {
  return float4(1.0f, 0.0f, 0.0f, 1.0f);
}
program_source:16:24: error: invalid type 'uint' (aka 'unsigned int') for input declaration in a vertex function
vertex float4 vtx_main(uint VertexIndex [[]]) {
                       ^~~~~~~~~~~~~~~~