# Equality and hashing disagree

Rule ID: correctness.equality-hash-contract@1.0.0. Availability below refers to source-scan at product 524fa07e.

## V-COR-01 — Equality and hashing disagree

Equality and hashing disagree. It examines value, collection, identity, ordering, and control-flow contracts.

### Availability

Not available in source-scan. There is no source-scan flag to activate this condition.

### Example and action

Illustrative design scenario, not a runnable Swift example or a reproduced analyzer result. The stated availability and evidence boundaries still apply.

**Before:** Two records compare equal by ID, but their hash also includes a mutable display name.

Review the following change against the contract and build variants described above.

**After:** Use the same stable identity fields for equality and hashing. Check equal values with different display names and avoid mutating identity while a value is a set member or dictionary key.

### Intended analysis

Intended reasoning: Compare the value, unit, identity or protocol assumptions at each operation. The intended conclusion requires consistent source identities and the relevant path constraints; an unrecognized abstraction can invalidate the comparison. Required evidence: value, identity, ordering, collection, and control-flow facts

### Assumptions and unknown

The relevant facts must be admitted for the selected immutable build world. Unknown aliases, external effects, unsupported source forms or incomplete consumers can prevent a conclusion. Availability in this workflow is stated above; the illustration does not expand that availability.

### Evidence and interpretation

The target catalog describes the intended condition. It is not evidence of an active source-scan diagnostic.

Historical evidence at 4558458d: accepted-subset (a limited set of source forms and profiles passed historical checks). That evidence has not been requalified for this product revision.

[How we validate checks](https://docs.swift-analyzer.com/concepts/validation/) explains the evidence boundary. [Foundations](https://docs.swift-analyzer.com/concepts/foundations/) separates method assumptions from implementation claims.


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Language: en
Canonical: https://docs.swift-analyzer.com/catalog/correctness.equality-hash-contract/
Product revision: 524fa07e0ae4153c84ac12ae9eb6559df89ec2be
Catalog revision: 4558458d
Documentation digest: 1f17ba58ab08627e0de898f1442067b09e960b48cd5605d6529e9275f8930d68
Channel: pre-prod; maturity: experimental; access: owner-provided checkout.