Preview 6 of Microsoft’s .NET 11 software development platform is now available, with improvements across the runtime, libraries, frameworks, and C# and F# programming languages.
Announced July 15, .NET 11 Preview 6 can be downloaded from dotnet.microsoft.com. The full, general production release is expected in November. The first preview was unveiled February 10.
Runtime-async, the .NET runtime’s built-in implementation of async/await, keeps getting faster in Preview 6, building on the suspension improvements from Preview 5. Async continuations can now opt out of ExecutionContext capture and restore. And the JIT now compiles a dedicated runtime-async version of a synchronous, task-returning method rather than delegating to it through a thunk. The JIT turns the method’s tail calls into runtime-async calls and awaits the task that would otherwise have been returned, so the async path no longer pays for an extra layer of indirection, Microsoft said.
In library improvements, System.Text.Json can now serialize and deserialize the new C# union types. The serializer recognizes a union through the new JsonTypeInfoKind.Union contract type, reads and writes the active case, and supports the reflection-based serializer and the source generator. The new JsonUnionAttribute, JsonUnionCaseInfo, and type-classifier APIs enable customization of how cases are discovered and named.
