Wrapping up

With our new definition of Platform in place, we can rewrite the previous code to make use of it! Here is an example of what you can do with freezed enums.

In lib/main.dart:

- final text = const {
-   Platform.Android: 'Android',
-   Platform.Ios: 'iOS',
-   Platform.MacApple: 'MacOS with Apple Silicon',
-   Platform.MacIntel: 'MacOS',
-   Platform.Windows: 'Windows',
-   Platform.Unix: 'Unix',
-   Platform.Wasm: 'the Web',
- }[platform] ??
- 'Unknown OS';
+ final text = platform.when(
+   android: () => 'Android',
+   ios: () => 'iOS',
+   macOs: (arch) => 'MacOS on $arch',
+   windows: () => 'Windows',
+   unix: () => 'Unix',
+   wasm: () => 'the Web',
+ );

In native/src/api.rs:

     } else if cfg!(target_os = "ios") {
         Platform::Ios
     } else if cfg!(all(target_os = "macos", target_arch = "aarch64")) {
-        Platform::MacApple
+        Platform::MacOs("Apple Silicon".into())
     } else if cfg!(target_os = "macos") {
-        Platform::MacIntel
+        Platform::MacOs("Intel".into())
     } else if cfg!(target_family = "wasm") {
         Platform::Wasm
     } else if cfg!(unix) {

When you flutter run, you should get something like this:

Tip: Using switch expressions

Introduced in Dart 3, switch expressions provide the equivalent of Rust's match expressions, complete with exhaustive checks. Instead of using when() in the above example, you could also use this syntax:

final text = switch (platform) {
  Platform_Android() => 'Android',
  Platform_Ios() => 'iOS',
  Platform_MacOs(:final arch) => 'MacOS on $arch',
  Platform_Windows() => 'Windows',
  Platform_Unix() => 'Unix',
  Platform_Wasm() => 'the Web',
  // we have covered all cases, so this compiles.
};