P2751 Evaluation of Checked Contracts

[wg21bot]

P2751R0 Evaluation of Checked Contracts (Joshua Berne)

[wg21bot]

P2751R1 Evaluation of Checked Contracts (Joshua Berne)

[timuraudio]

Integrated into P2900 in Varna:
https://wiki.edg.com/bin/view/Wg21issaquah2023/SG21MinutesFeb7th

[timuraudio]

Partially adopted by SG21 for P2900.

2023-02-09, Issaquah

When the evaluation of a contract-checking predicate exits the control flow other than by returning or throwing (for example, abort or longjmp), the behaviour is as if it were not in a contract-checking predicate.
SF | F | N | A | SA
19 | 11 | 0 | 1 | 0
Result: Consensus

We would like to non-normatively state the recommended practice that implementations should consider treating undefined behavior in the evaluation of a contract predicate as a contract violation.
SF | F | N | A | SA
5 | 11 | 5 | 2 | 8
Result: Not consensus

We want to adopt the rules on reordering the evaluation of contract-checking predicates as described in P2751R0 proposal 3.4, contingent on a clarification that this reordering can be equivalently formulated in terms of elision of evaluations inside repetitions of the given sequence of predicates.
SF | F | N | A | SA
12 | 5 | 3 | 1 | 0
Result: Consensus