Apple Developer Documentation

Strict Concurrency Checking

Setting name: SWIFT_STRICT_CONCURRENCY

This setting controls the level of Sendable enforcement and actor-isolation checking performed by the Swift compiler.

• Minimal: Enforce Sendable constraints only where it has been explicitly adopted and perform actor-isolation checking wherever code has adopted concurrency.
• Targeted: Enforce Sendable constraints and perform actor-isolation checking wherever code has adopted concurrency, including code that has explicitly adopted Sendable.
• Complete: Enforce Sendable constraints and actor-isolation checking throughout the entire module.