Update for Flutter 3.10 beta (#1746)

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [ ] All existing and new tests are passing.

---------

Co-authored-by: David Iglesias <ditman@gmail.com>
Co-authored-by: Mark Thompson <2554588+MarkTechson@users.noreply.github.com>
Co-authored-by: John Ryan <ryjohn@google.com>

simplistic_calculator/lib/main.dart

@@ -101,29 +101,30 @@ class CalculatorEngine extends StateNotifier<CalculatorState> {
       final exp = parser.parse(state.buffer);
       final result = exp.evaluate(EvaluationType.REAL, cm) as double;
 
-      if (result.isInfinite) {
-        state = state.copyWith(
-          error: 'Result is Infinite',
-          buffer: '',
-          mode: CalculatorEngineMode.result,
-        );
-      } else if (result.isNaN) {
-        state = state.copyWith(
-          error: 'Result is Not a Number',
-          buffer: '',
-          mode: CalculatorEngineMode.result,
-        );
-      } else {
-        final resultStr = result.ceil() == result
-            ? result.toInt().toString()
-            : result.toString();
-        state = state.copyWith(
-            buffer: resultStr,
+      switch (result) {
+        case double(isInfinite: true):
+          state = state.copyWith(
+            error: 'Result is Infinite',
+            buffer: '',
             mode: CalculatorEngineMode.result,
-            calcHistory: [
-              '${state.buffer} = $resultStr',
-              ...state.calcHistory,
-            ]);
+          );
+        case double(isNaN: true):
+          state = state.copyWith(
+            error: 'Result is Not a Number',
+            buffer: '',
+            mode: CalculatorEngineMode.result,
+          );
+        default:
+          final resultStr = result.ceil() == result
+              ? result.toInt().toString()
+              : result.toString();
+          state = state.copyWith(
+              buffer: resultStr,
+              mode: CalculatorEngineMode.result,
+              calcHistory: [
+                '${state.buffer} = $resultStr',
+                ...state.calcHistory,
+              ]);
       }
     } catch (err) {
       state = state.copyWith(
@@ -465,9 +466,10 @@ class CalcButton extends ConsumerWidget {
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
-    final buttonConstructor = type == CalcButtonType.elevated
-        ? ElevatedButton.new
-        : OutlinedButton.new;
+    final buttonConstructor = switch (type) {
+      CalcButtonType.elevated => ElevatedButton.new,
+      _ => OutlinedButton.new,
+    };
 
     return SizedBox.expand(
       child: Padding(