FA-43312 / Borrow checking / Member archive

An operand borrow ends one evaluation step before the full expression · case 02

An operand borrow ends one evaluation step before the full expression.

Member previewVariant 2 · 3 implementations · 21 checks per implementation

Case contract

Check temporary storage scopes using statement, block and full-expression integer boundaries. A borrowed temporary must cover use points; ordinary call arguments end at call boundary; let reference initializers may extend to block end but assignment RHS may not; operand temporaries end after enclosing expression; condition temporaries cannot leak into the then block; short-circuit RHS temporaries exist only on executed branch; a destructor observation is a use point; a reference to a promoted constant uses static storage; explicit owner binding prevents premature temporary destruction. 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
operand-expression regression 0	`[]`	`["operand-expression"]`	Failed

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