// `?(?i64)` is `optional` wrapping the SINGLE-FIELD TUPLE `(?i64)` — in type
// position `(T)` is a 1-tuple, not a grouping (specs.md §"Tuple Types"). So
// assigning a bare `?i64` value to a `?(?i64)` slot is a type mismatch: the
// optional's payload is the tuple `(?i64)`, not `?i64`.
//
// Regression (issue 0165): this used to silently lower to a malformed
// `insertvalue { {{i64,i1}}, i1 }` that aborted the LLVM verifier. It now
// produces a clean diagnostic naming the payload type and pointing at the
// parens-are-a-tuple gotcha. (To write a genuine nested optional, alias the
// inner one: `Opt :: ?i64; x : ?Opt = ...` — see
// examples/optionals/0911-nested-optional-via-alias.sx.)
#import "modules/std.sx";

main :: () {
  inner : ?i64 = 5;
  outer : ?(?i64) = inner;
  print("unreachable\n");
}