// Nested optional `?(?i64)` written via a type alias — `Opt :: ?i64; ?Opt`.
// The outer optional's payload is the inner optional, so the layout is the
// well-formed double-wrap `{ {i64,i1}, i1 }`. Assigning an inner `?i64`,
// unwrapping the outer to recover the inner `?i64`, and unwrapping that all
// round-trip cleanly.
//
// Regression (issue 0165): the type-table interning always produced the
// correct `{ {i64,i1}, i1 }` for a genuine nested optional — this locks that in.
#import "modules/std.sx";

Opt :: ?i64;

main :: () {
  inner : ?i64 = 5;
  outer : ?Opt = inner;        // ?(?i64) — payload is the inner optional

  print("outer present: {}\n", outer != null);

  mid := outer!;               // unwrap outer  -> ?i64
  print("mid present: {}\n", mid != null);
  print("value: {}\n", mid!);  // unwrap inner  -> 5

  // null-coalesce through the recovered inner optional
  print("coalesced: {}\n", mid ?? 0);

  // a none outer
  empty : ?Opt = null;
  print("empty present: {}\n", empty != null);
}