FA-43210 / Borrow checking / Member archive

A suspended exclusive loan retains a caller-visible alias · case 05

A suspended exclusive loan retains a caller-visible alias.

Member previewVariant 5 · 3 implementations · 21 checks per implementation

Case contract

Validate static generator suspension descriptors. Live borrowed stack origins must be stored in the frame; movable frames cannot retain self references; pinned self references require pinned projection; a saved unique loan cannot have external aliases; suspension-disallowed guards cannot cross yield; resumed references must survive every resume point; cancellation drop order releases borrowers before owners; references returned by a completed generator cannot target its frame; loans killed before yield must not be saved; mutually exclusive variants require variant-specific frame loans. Input is a fully explicit descriptor of the stated toy IR. Return rule identifiers in declaration order; absent optional obligations use the provided neutral defaults. No rule is an assertion about a production language.

Why this case matters

A finite offline static-analysis model of ownership and borrowing; it does not execute the analyzed program.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
suspended-unique-alias regression 0	`[]`	`["suspended-unique-alias"]`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.