Tag: csharp-14

CS4014 means you called a Task-returning method without awaiting it. Add await, or discard with _ = if fire-and-forget is truly intended, and handle exceptions.

CS8618 means a non-nullable field or property was not initialized by the time the constructor finished. Set it in the constructor, give it a default, mark it required, or make it nullable.

CS9035 means a member marked required was not assigned. Set it in the object initializer, or add a constructor annotated with [SetsRequiredMembers] that assigns every required member.

Extension properties land in C# 14 through the new extension block. Declare get-only, settable, static, and generic extension properties, why auto-properties are rejected, and how the compiler lowers them to get_/set_ accessors.

A version-pinned migration checklist from .NET 8 LTS to .NET 11 LTS, covering SDK install, csproj target framework, breaking changes in ASP.NET Core, EF Core, System.Text.Json, and the C# 14 overload-resolution shift, with rollback notes.

After upgrading to C# 14 / .NET 10, calls like array.Contains, x.Reverse(), and MemoryMarshal.Cast suddenly bind to different overloads or stop compiling. Here is what changed and how to pin the old behaviour where it matters.

Build a working Model Context Protocol server in C# 14 / .NET 11 using the official ModelContextProtocol 1.2 SDK. Covers stdio transport, [McpServerTool] attributes, dependency injection, the stderr logging trap, and registration with Claude Code, Claude Desktop, and VS Code.

Stream a multi-gigabyte CSV in .NET 11 without OutOfMemoryException. File.ReadLines, CsvHelper, Sylvan, and Pipelines compared with code and measurements.

Seven ways to return more than one value from a C# 14 method: named tuples, out parameters, records, structs, deconstruction, and the extension-member trick for types you don't own. Real benchmarks and a decision matrix at the end.

C# 14 lets you overload +=, -=, *=, and friends as void instance methods that mutate the receiver in place, cutting allocations for large value holders like BigInteger-style buffers and tensors.