Add an example of using UnscopedRefAttribute to fix CS8170
#47078
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Thanks again @BartoszKlonowski
I had a couple questions to look at before we merge this. Let me know your thoughts.
| public void Method() | ||
| { | ||
| var p = new Program(); | ||
| var d = p.M(); |
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Should this use = ref?
| var d = p.M(); | |
| ref int d = ref p.M(); |
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Indeed - However, because I generally used the exact same example as the one showing the CS8170, I also updated the original with this suggestion.
| @@ -83,3 +83,30 @@ public class Other | |||
| } | |||
| } | |||
| ``` | |||
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| Another approach is to use the <xref:System.Diagnostics.CodeAnalysis.UnscopedRefAttribute?displayProperty=nameWithType> attribute. It will mark the reference to be allowed to escape the scope. | |||
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This is great, but I think it's worth pointing out the danger here: you really need to know that the ref can escape safely.
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Please check with the latest, as I added the "warning" for being sure about the safety of leaving the scope.
Let me know, please if there's some other wording you think would suit this better.
This pull request fixes #46499
It adds the example of how
UnscopedRefAttributecan be used to mark a method through which a ref is allowed to escape the scope.I didn't add the "See also" section with a link to this attribute, because it is already linked twice when mentioned.
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