macro

It seems like you're interested in the use of macros in Swift, as discussed in various sessions at WWDC. Here are some highlights:

1. Expect and Require Macros: In the session "Meet Swift Testing," the expect macro is highlighted for its flexibility in testing. It allows you to pass any expression, including operators and method calls, and provides detailed results if it fails. The require macro is used to end a test early if an expectation fails, throwing an error if the expression is false. This is particularly useful for safely unwrapping optional values. You can learn more about these macros in the Meet Swift Testing session.

2. Index Macro in SwiftData: The session "What’s new in SwiftData" introduces the index macro, which can be used to enhance the performance of your app by adding unique constraints to your schema. This helps in avoiding duplicate models and speeding up queries. More details can be found in the What’s new in SwiftData session.

3. Playground Macro in Xcode: In the session "What’s new in Xcode," a new macro called Playground is introduced. It allows for quick iteration on any code, similar to previews, by adding a playground inline in your document. This feature is demonstrated in the What’s new in Xcode session.

These sessions provide a comprehensive overview of how macros can be utilized to enhance testing, data management, and code iteration in Swift.