static void TestStructCasts()
{
PromotedStruct a = new PromotedStruct(); // Addr-exposed, cannot be promoted.promotedField.
a.promotedField.pointerSizedField = 4;
a.anotherField = 5;
NotPromotedStruct b = PromotedStruct.AsNotPromotedStruct(ref a);
// The cast can be inlined and the field handle will refer to the `PromotedStruct.pointerSizedField`,
// in this case we can promote it because `NotPromotedStruct.notPromotedField.pointerSizedField` has
// the same class handle.
Debug.Assert(b.notPromotedField.pointerSizedField == 0x4);
NotPromotedStruct c = PromotedStruct.AsNotPromotedStruct(ref a);
// The cast can be inlined and the field handle will refer to the `PromotedStruct.pointerSizedField`,
// in this case we cannot promote it because `NotPromotedStruct.anotherOverlappingStruct.a` has
// a different class handle (`NotPromotedStruct.anotherOverlappingStruct`).
Debug.Assert(c.anotherOverlappingStruct.a == 0x4);
Debug.Assert(c.anotherOverlappingStruct.b == 0x5);
}
public static ref PromotedStruct AsPromotedStructSize20(ref NotPromotedStruct d) => ref Unsafe.As <NotPromotedStruct, PromotedStruct>(ref d);
