csharp / expert
Snippet
Implementing Custom Awaiters
In C#, any type can be awaited if it follows the 'GetAwaiter' pattern. This expert-level technique allows you to create custom asynchronous primitives without relying on Task or ValueTask, reducing allocation overhead in specialized high-performance scenarios.
snippet.cs
csharp
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public struct MyTaskAwaiter : INotifyCompletion {public bool IsCompleted => false;public void OnCompleted(Action continuation) => Task.Run(continuation);public void GetResult() { }}public struct MyCustomTask {public MyTaskAwaiter GetAwaiter() => new MyTaskAwaiter();}
Breakdown
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public bool IsCompleted => false;
Determines if the operation is already finished; if false, the state machine yields.
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public MyTaskAwaiter GetAwaiter()
The duck-typing method the compiler looks for to enable the 'await' keyword.