Query no longer compiles in 8.8.8, did in 8.8.7

cmd · March 18

Hey Joe!

Hopefully this is an easy one or a me issue.

It seems something changed between 8.8.7 and 8.8.8, where a query that was making use of something from System.Linq is now catching something from System.MemoryExtensions instead. (The thing I noticed specifically is the Reverse<T>() method, since the Linq one returns an enumerable while the memory extensions one operates in-place.)

The query doesn't specifically call out any using for System.MemoryExtensions, but it seems that it's tokens are clobbering the System.Linq ones. I don't see any way to opt out of that behavior, other than invoking the desired extension method explicitly.

Here's a screenshot with a small repro. 8.8.8 is on the left (with the 'fail to compile',) and 8.8.7 is on the right.

Thanks for all your awesome work!

sgmoore · March 18

Do you have C# preview features enabled?

Sounds like https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/first-class-span-types#calling-reverse-on-an-array

i2van · March 19

@sgmoore said:
Do you have C# preview features enabled?

Sounds like https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/first-class-span-types#calling-reverse-on-an-array

It compiles if preview disabled.

cmd · March 27

Fantastic catch, sgmoore — definitely looks like it. I do in fact have preview features enabled; Just like i2van points out, it compiles as I had expected with them off. The workaround of manually applying Enumerable.Reverse() looks easy enough to apply where I've got the issue.

Cheers to the both of you.

Query no longer compiles in 8.8.8, did in 8.8.7

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