### Check introductory offer eligibility

Source: https://developer.apple.com/documentation/ios-ipados-release-notes/ios-ipados-18_4-release-notes

Returns false if no user account is signed in. Ensure the user is signed in with their App Store account to request eligibility.

```swift
isEligibleForIntroOffer(for:)
```

--------------------------------

### Configure URLSession loading mode

Source: https://developer.apple.com/documentation/ios-ipados-release-notes/ios-ipados-18_4-release-notes

Set usesClassicLoadingMode to false to enable the new HTTP loading mode.

```swift
usesClassicLoadingMode
```

--------------------------------

### Enable availability checking for hvf

Source: https://developer.apple.com/documentation/ios-ipados-release-notes/ios-ipados-18_4-release-notes

Add this macro definition before any headers to enable availability checking for C APIs in hvf.

```c
 #define BUILD_FOR_APPLE_SDK 1

```

--------------------------------

### Handle Preferred Color Scheme in SwiftUI

Source: https://developer.apple.com/documentation/ios-ipados-release-notes/ios-ipados-18_1-release-notes

This snippet demonstrates how to manage the preferred color scheme in SwiftUI views. Passing `nil` to `.preferredColorScheme` defers to the system's color scheme.

```swift
.preferredColorScheme(isDarkMode ? .dark : nil)
```

--------------------------------

### Manage transaction entitlements

Source: https://developer.apple.com/documentation/ios-ipados-release-notes/ios-ipados-18_4-release-notes

Deprecated API for retrieving current entitlements. Use Transaction.currentEntitlements(for:) to include family shared subscriptions.

```swift
Transaction.currentEntitlement(for:)
```

--------------------------------

### Apply view modifiers in SwiftUI

Source: https://developer.apple.com/documentation/ios-ipados-release-notes/ios-ipados-18_4-release-notes

Modifiers for controlling tint colors, toolbar visibility, and preference changes.

```swift
tint(_:)
```

```swift
defaultVisibility(.hidden)
```

```swift
.onPreferenceChange
```

--------------------------------

### NavigationSplitView Dismissal Behavior

Source: https://developer.apple.com/documentation/ios-ipados-release-notes/ios-ipados-18-release-notes

Demonstrates the use of DismissAction within a DetailView to clear sidebar selections in a NavigationSplitView.

```swift
 NavigationSplitView {
   List(…)
 } detail: {
   DetailView()
 }
 
 struct DetailView: View {
   @Environment(\.dismiss) private var dismiss
 
   var body: some View { 
     Button("Pop") { dismiss() }
   }
 }
```

--------------------------------

### Apply presentation sizing to a sheet

Source: https://developer.apple.com/documentation/ios-ipados-release-notes/ios-ipados-18-release-notes

Use the presentationSizing modifier to explicitly define the sizing behavior of a sheet, which defaults to .automatic in iOS 18.

```swift
 ContentView().sheet(isPresented: $present) {
   SheetView().presentationSizing(.form)
 }
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.