Deconstruction into a pointer target ((*p, value) = tuple;) stayed an
explicit Deconstruct call: a store through a pointer (or through a target
whose pointer type got erased in a stack slot) does not infer a
ByReferenceType, so IsAssignment reported an unknown expected type and the
transform's conversion check rejected the assignment. The type of the store
itself is just as precise, so use it as the expected type.
Of the three IsAssignment call sites only the transform's MatchAssignment
consumes the expected type; CheckInvariant and GetAssignmentIndex discard
it, so this widens what the transform accepts without weakening the
invariant check.
Assisted-by: Claude:claude-opus-5:Claude Code