---
title: "defaultIsolation(_:_:)"
framework: packagedescription
role: symbol
role_heading: Type Method
path: "packagedescription/swiftsetting/defaultisolation(_:_:)"
---

# defaultIsolation(_:_:)

Set the default isolation to the given global actor type.

## Declaration

```swift
static func defaultIsolation(_ isolation: MainActor.Type?, _ condition: BuildSettingCondition? = nil) -> SwiftSetting
```

## Parameters

- `isolation`: The type of global actor to use for default actor isolation inference. The only valid arguments are MainActor.self and nil.
- `condition`: A condition that restricts the application of the build setting.

## Discussion

Discussion note: First available in PackageDescription 6.2. The compiler defaults to inferring unannotated code as nonisolated if unspecified, or if the isolation parameter is set to nil.

## See Also

### Configuring Swift Settings

- [define(_:_:)](packagedescription/swiftsetting/define(_:_:).md)
- [unsafeFlags(_:_:)](packagedescription/swiftsetting/unsafeflags(_:_:).md)
- [strictMemorySafety(_:)](packagedescription/swiftsetting/strictmemorysafety(_:).md)
- [swiftLanguageMode(_:_:)](packagedescription/swiftsetting/swiftlanguagemode(_:_:).md)
- [enableExperimentalFeature(_:_:)](packagedescription/swiftsetting/enableexperimentalfeature(_:_:).md)
- [enableUpcomingFeature(_:_:)](packagedescription/swiftsetting/enableupcomingfeature(_:_:).md)
- [interoperabilityMode(_:_:)](packagedescription/swiftsetting/interoperabilitymode(_:_:).md)
- [SwiftSetting.InteroperabilityMode](packagedescription/swiftsetting/interoperabilitymode.md)
- [swiftLanguageVersion(_:_:)](packagedescription/swiftsetting/swiftlanguageversion(_:_:).md)