assumeIsolated — Synchronous Actor Access

Synchronously access actor-isolated state when you know you're already on the correct isolation domain.

When to Use

✅ Use when:

• Testing MainActor code synchronously (avoiding Task overhead)
• Legacy delegate callbacks documented to run on main thread
• Performance-critical code avoiding async hop overhead
• Protocol conformances where callbacks are guaranteed on specific actor

❌ Don't use when:

• Uncertain about current isolation (use await instead)
• Already in async context (you have isolation)
• Cross-actor calls needed (use async)
• Callback origin is unknown or untrusted

API Reference