Swift Upcoming Feature Flags Cheatsheet

This is a cheatsheet for applying Swift's Upcoming Feature Flags to your Package.swift easily.

Note

This cheatsheet only includes those that have been implemented in the release. It does not include accepted ones, etc.
This does not include Experimental Features.

Usage

Copy and paste either "Short" or "Full" into your Package.swift.

import PackageDescription

// Paste here 📋

let package = Package(
    name: "Package Name",
    targets: [
        .target(
            name: "Target Name",
            swiftSettings: [
                .existentialAny // <-- Specify easily using completion 🥳
            ]
        )
    ]
)

Or, copy and paste the CaseIterable Conformance as needed.

import PackageDescription

// Paste here 📋

let package = Package(
    name: "Package Name",
    targets: [
        .target(
            name: "Target Name"
        )
    ]
)

// Set all flags to targets 🎉
package.targets
    .filter { ![.system, .binary, .plugin].contains($0.type) }
    .forEach { $0.swiftSettings = SwiftSetting.allCases }

Choose the swift-tools-version

Tip

If you are using swift-tools-version 6.0 and have Swift language mode 5 for the entire package or per target, you may want to use a combination of both.

For swift-tools-version 6.0 (Swift 6.0)

Short

import PackageDescription

extension SwiftSetting {
    static let existentialAny: Self = .enableUpcomingFeature("ExistentialAny")                      // SE-0335, Swift 5.6,  SwiftPM 5.8+
    static let internalImportsByDefault: Self = .enableUpcomingFeature("InternalImportsByDefault")  // SE-0409, Swift 6.0,  SwiftPM 6.0+
}

CaseIterable Conformance

extension SwiftSetting: @retroactive CaseIterable {
    public static var allCases: [Self] {[.existentialAny, .internalImportsByDefault]}
}

Full

import PackageDescription

extension SwiftSetting {
    /// Introduce existential `any`
    /// - Version: Swift 5.6
    /// - Since: SwiftPM 5.8
    /// - SeeAlso: [SE-0335: Introduce existential `any`](https://github.com/apple/swift-evolution/blob/main/proposals/0335-existential-any.md)
    static let existentialAny: Self = .enableUpcomingFeature("ExistentialAny")
    /// Access-level modifiers on import declarations
    /// - Version: Swift 6.0
    /// - Since: SwiftPM 6.0
    /// - SeeAlso: [SE-0409: Access-level modifiers on import declarations](https://github.com/swiftlang/swift-evolution/blob/main/proposals/0409-access-level-on-imports.md)
    static let internalImportsByDefault: Self = .enableUpcomingFeature("InternalImportsByDefault")
}

CaseIterable Conformance

extension SwiftSetting: @retroactive CaseIterable {
    public static var allCases: [Self] {
        [
            .existentialAny,
            .internalImportsByDefault,
        ]
    }
}

For swift-tools-version 5.8 to 5.10 (Swift 5.8 - 5.10)

Short

import PackageDescription

extension SwiftSetting {
    static let forwardTrailingClosures: Self = .enableUpcomingFeature("ForwardTrailingClosures")              // SE-0286, Swift 5.3,  SwiftPM 5.8+
    static let existentialAny: Self = .enableUpcomingFeature("ExistentialAny")                                // SE-0335, Swift 5.6,  SwiftPM 5.8+
    static let bareSlashRegexLiterals: Self = .enableUpcomingFeature("BareSlashRegexLiterals")                // SE-0354, Swift 5.7,  SwiftPM 5.8+
    static let conciseMagicFile: Self = .enableUpcomingFeature("ConciseMagicFile")                            // SE-0274, Swift 5.8,  SwiftPM 5.8+
    static let importObjcForwardDeclarations: Self = .enableUpcomingFeature("ImportObjcForwardDeclarations")  // SE-0384, Swift 5.9,  SwiftPM 5.9+
    static let disableOutwardActorInference: Self = .enableUpcomingFeature("DisableOutwardActorInference")    // SE-0401, Swift 5.9,  SwiftPM 5.9+
    static let deprecateApplicationMain: Self = .enableUpcomingFeature("DeprecateApplicationMain")            // SE-0383, Swift 5.10, SwiftPM 5.10+
    static let isolatedDefaultValues: Self = .enableUpcomingFeature("IsolatedDefaultValues")                  // SE-0411, Swift 5.10, SwiftPM 5.10+
    static let globalConcurrency: Self = .enableUpcomingFeature("GlobalConcurrency")                          // SE-0412, Swift 5.10, SwiftPM 5.10+
}

CaseIterable Conformance

extension SwiftSetting: CaseIterable {
    public static var allCases: [Self] {[.forwardTrailingClosures, .existentialAny, .bareSlashRegexLiterals, .conciseMagicFile, .importObjcForwardDeclarations, .disableOutwardActorInference, .deprecateApplicationMain, .isolatedDefaultValues, .globalConcurrency]}
}

Full

import PackageDescription

extension SwiftSetting {
    /// Forward-scan matching for trailing closures
    /// - Version: Swift 5.3
    /// - Since: SwiftPM 5.8
    /// - SeeAlso: [SE-0286: Forward-scan matching for trailing closures](https://github.com/apple/swift-evolution/blob/main/proposals/0286-forward-scan-trailing-closures.md)
    static let forwardTrailingClosures: Self = .enableUpcomingFeature("ForwardTrailingClosures")
    /// Introduce existential `any`
    /// - Version: Swift 5.6
    /// - Since: SwiftPM 5.8
    /// - SeeAlso: [SE-0335: Introduce existential `any`](https://github.com/apple/swift-evolution/blob/main/proposals/0335-existential-any.md)
    static let existentialAny: Self = .enableUpcomingFeature("ExistentialAny")
    /// Regex Literals
    /// - Version: Swift 5.7
    /// - Since: SwiftPM 5.8
    /// - SeeAlso: [SE-0354: Regex Literals](https://github.com/apple/swift-evolution/blob/main/proposals/0354-regex-literals.md)
    static let bareSlashRegexLiterals: Self = .enableUpcomingFeature("BareSlashRegexLiterals")
    /// Concise magic file names
    /// - Version: Swift 5.8
    /// - Since: SwiftPM 5.8
    /// - SeeAlso: [SE-0274: Concise magic file names](https://github.com/apple/swift-evolution/blob/main/proposals/0274-magic-file.md)
    static let conciseMagicFile: Self = .enableUpcomingFeature("ConciseMagicFile")
    /// Importing Forward Declared Objective-C Interfaces and Protocols
    /// - Version: Swift 5.9
    /// - Since: SwiftPM 5.9
    /// - SeeAlso: [SE-0384: Importing Forward Declared Objective-C Interfaces and Protocols](https://github.com/apple/swift-evolution/blob/main/proposals/0384-importing-forward-declared-objc-interfaces-and-protocols.md)
    static let importObjcForwardDeclarations: Self = .enableUpcomingFeature("ImportObjcForwardDeclarations")
    /// Remove Actor Isolation Inference caused by Property Wrappers
    /// - Version: Swift 5.9
    /// - Since: SwiftPM 5.9
    /// - SeeAlso: [SE-0401: Remove Actor Isolation Inference caused by Property Wrappers](https://github.com/apple/swift-evolution/blob/main/proposals/0401-remove-property-wrapper-isolation.md)
    static let disableOutwardActorInference: Self = .enableUpcomingFeature("DisableOutwardActorInference")
    /// Deprecate `@UIApplicationMain` and `@NSApplicationMain`
    /// - Version: Swift 5.10
    /// - Since: SwiftPM 5.10
    /// - SeeAlso: [SE-0383: Deprecate `@UIApplicationMain` and `@NSApplicationMain`](https://github.com/apple/swift-evolution/blob/main/proposals/0383-deprecate-uiapplicationmain-and-nsapplicationmain.md)
    static let deprecateApplicationMain: Self = .enableUpcomingFeature("DeprecateApplicationMain")
    /// Isolated default value expressions
    /// - Version: Swift 5.10
    /// - Since: SwiftPM 5.10
    /// - SeeAlso: [SE-0411: Isolated default value expressions](https://github.com/apple/swift-evolution/blob/main/proposals/0411-isolated-default-values.md)
    static let isolatedDefaultValues: Self = .enableUpcomingFeature("IsolatedDefaultValues")
    /// Strict concurrency for global variables
    /// - Version: Swift 5.10
    /// - Since: SwiftPM 5.10
    /// - SeeAlso: [SE-0412: Strict concurrency for global variables](https://github.com/apple/swift-evolution/blob/main/proposals/0412-strict-concurrency-for-global-variables.md)
    static let globalConcurrency: Self = .enableUpcomingFeature("GlobalConcurrency")
}

CaseIterable Conformance

extension SwiftSetting: CaseIterable {
    public static var allCases: [Self] {
        [
            .forwardTrailingClosures,
            .existentialAny,
            .bareSlashRegexLiterals,
            .conciseMagicFile,
            .importObjcForwardDeclarations,
            .disableOutwardActorInference,
            .deprecateApplicationMain,
            .isolatedDefaultValues,
            .globalConcurrency,
        ]
    }
}

License

This cheatsheet by @treastrain is marked with CC0 1.0 Universal. To view a copy of this license, visit http://creativecommons.org/publicdomain/zero/1.0?ref=chooser-v1