Type and Deconstruction Simultaneously

[zms9110750]

Type of issue

Missing information

Description

I found a usage method that did not appear in the document.

public abstract record Result<T> : IDisposable
{
	public sealed record Ok(T Value) : Result<T>;

	//...

	public T GetValueOrDefault()
	{
		switch (this)
		{
			case Ok(T Value):
				return Value;
		}
		return default(T)!;
	}
//...
}

Page URL

https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/patterns

Content source URL

https://github.com/dotnet/docs/blob/main/docs/csharp/language-reference/operators/patterns.md

Document Version Independent Id

312e9c81-ee2a-1d84-64d7-bcaa71d7eab8

Article author

@BillWagner

Metadata

• ID: 9112c305-f1cd-1aa5-4557-2c7d757e6ca0
• Service: dotnet-csharp
• Sub-service: lang-reference

---

Associated WorkItem - 310181

[BillWagner]

Hi @zms9110750

Can you add an example where this is useful? I find the code interesting, but I'm not seeing a scenario where I'd use it in practice.

[zms9110750]

你好@zms9110750

您能添加一个有用的例子吗？我发现代码很有趣，但我没有看到在实践中使用它的场景。

I just saw this grammar here
I didn't realize this grammar until then, and the document didn't introduce it. So I think he should be supplemented.
I don't know the usage scenarios in practice, so I can't answer you.

[zms9110750]

If the positional pattern relies entirely on Deconstruct, I think it would be better to directly change the title to Deconstruct pattern.

[dotnet-policy-service]

This issue has been automatically closed due to no response from the original author. Feel free to reopen it if you have more information that can help us investigate the issue further.

[zms9110750]

@BillWagner hi?

[BillWagner]

Hi @zms9110750

Thanks for tagging me in that comment. I missed the earlier once, and it looks like one of our bots didn't restore labels correctly on your last comment.

I see your point. I'm not going to change the name. We chose that to match the name used in the specification. However, I did add a callout on the importance of order.