#Ownership

Let the signature express who owns the value and how long it is needed.

#Borrowing and state

#Why

Cloning a value to escape an ownership error can obscure the relationship the compiler is asking you to model.

#Rules

• MUST borrow read-only inputs when ownership is unnecessary. [review]

• MUST return a new value for a domain state transition rather than mutate the caller's value. [review]

• MUST avoid shared mutable domain state through RefCell, locks, or atomics merely for convenience. [review]

• MUST justify clones with a real ownership or lifetime requirement. [review]

• MUST keep mutable handles and synchronization for external resources in their owning adapters. [review]

• MUST prefer owned outputs over references to local temporaries. [review]

• MUST choose a collection from its semantics without copying TypeScript-specific collection bans into Rust. [review]

[review]

The borrow checker establishes memory ownership constraints. Review checks deliberate clones, interior mutation, and domain/resource separation.

#Enforcement

The borrow checker establishes memory ownership constraints. Review checks deliberate clones, interior mutation, and domain/resource separation.