Cairo References and Snapshots

Overview

Explain when to pass by value, snapshot, or mutable reference, and how to read or mutate safely.

Quick Use

• •Read references/references-snapshots.md before answering.
• •Show the correct parameter form (value, @value, or ref value).
• •Use *snapshot only for Copy types.

Response Checklist

• •Use snapshots (@T) to read without moving ownership.
• •Use ref when the callee must mutate and the caller must regain ownership.
• •Remind that ref requires a mut variable at the call site.
• •Call out that snapshots are immutable and cannot be mutated directly.

Example Requests

• •"Why does passing this array move ownership?"
• •"How do I modify a struct inside a function and keep it?"
• •"What does @ mean in a type annotation?"

Cairo by Example

• •Retaining Ownership
• •Snapshots
• •References