Champion: Unmanaged constructed types (16.3, Core 3)

[agocke]

• Proposed: Champion: Unmanaged constructed types (16.3, Core 3) #1744
• Prototype: Not needed
• Implementation: Complete
• Specification: Described in Champion: Unmanaged constructed types (16.3, Core 3) #1744

[xoofx]

@agocke hey, any news on this? We are getting seriously blocked by this at Unity and this is becoming more urgent. How can we help to push for this?

[xoofx]

A few questions:

• Is there any other changes to the spec than what I described here?
• Prototype/Implementation wise, can you confirm that it should be fairly easy to fix this in Roslyn? (apart unlocking the check and adding some tests related to this?)

[agocke]

@xoofx This has been approved and @RikkiGibson is almost done with his implementation. Expected release: C# 8.0 😄

[xoofx]

@xoofx This has been approved and @RikkiGibson is almost done with his implementation. Expected release: C# 8.0

Cool! Is it accessible in a branch?

[agocke]

@xoofx Just linked to the branch.

[xoofx]

yep, just saw that, 😅 thanks!

[abelbraaksma]

@agocke, for reference, maybe it's better to link to the PR directly? I believe it's this one: dotnet/roslyn#31148

[PathogenDavid]

There's sometimes more than one PR for each feature branch. For instance: dotnet/roslyn#31597 also applies to this feature.

When you look at the commits in the branch, you can see the pull requests there: https://github.com/dotnet/roslyn/commits/features/unmanaged-constructed-types So if you want to read the code reviews and such, you're probably best off going through there.

[abelbraaksma]

@PathogenDavid, thanks, that helps :)

[hypeartist]

Hmmm... Seems like the link (https://github.com/dotnet/roslyn/commits/features/unmanaged-constructed-types) is outdated? It gives me 404 error.

[PathogenDavid]

It was merged into the dev16.1-preview1 branch.

Based on dotnet/roslyn#31374 (comment), I think development on feature is considered to have been completed.

[RikkiGibson]

Sorry, I forgot to check the box for "implementation" :)

Yes, the feature is now in Roslyn's master branch. It won't ship until dev16.1-preview1.

[dzmitry-lahoda]

    public interface IEntity<TId>
        where TId : unmanaged
    {
        TId Id { get; }
    }
   public interface ISkill : IEntity<(byte, byte)>
   {
   }

Severity	Code	Description	Project	File	Line	Suppression State
Error	CS8377	The type '(byte, byte)' must be a non-nullable value type, along with all fields at any level of nesting, in order to use it as parameter 'TId' in the generic type or method 'IEntity<TId>'	

ValueTuple<T1,T2> has no where T1 : unmanaged where T2 : unmanaged. But in case presented it seems unmanaged.

Will(can) ValueTuple be supported as part of implementation?

As broader picture, I am writing serialization engine SergeyTeplyakov/ObjectLayoutInspector#15 which may support more cases, if generic structs not constrained by unmanaged at declaration side, but still closed on generics at usage side, could still be considered unmanaged.

[xoofx]

@dzmitry-lahoda are you using the Roslyn dev16.1-preview1? (afaik, it is not shipped in any VS2019, you have to fetch the compiler yourself) otherwise I would expect it to work with what did @RikkiGibson

[xoofx]

This issue can be closed right?

[PathogenDavid]

@xoofx Not saying it isn't a little weird, but the champion issues for completed C# features are never closed. (See comments here, or here by @gafter)

[HaloFour]

@xoofx

IIRC the issue is kept open until the spec and doc work is also complete.

[xoofx]

Oh, ok thanks, sorry for the noise 😅