Use 'required' members when targeting net6.0;net7.0

[tmds]

I'd like to use required members for a project that targets both net6.0 and net7.0.

The .NET 6 build gives build errors for missing attributes that were introduced in .NET 7 to support required members:

error CS0656: Missing compiler required member 'System.Runtime.CompilerServices.RequiredMemberAttribute..ctor'
error CS0656: Missing compiler required member 'System.Runtime.CompilerServices.CompilerFeatureRequiredAttribute..ctor'
error CS0656: Missing compiler required member 'System.Diagnostics.CodeAnalysis.SetsRequiredMembersAttribute..ctor'

Can I add some package that defines these attributes, or define them myself to make the build work?

[HaloFour]

Officially, C# 11 is only supported on .NET 7.0 and newer. Microsoft doesn't provide assemblies to polyfill older runtimes.

See: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/configure-language-version

You can provide your own, though, and there may be third-party NuGet packages out there to do the same.

[Sergio0694]

"Can I add some package that defines these attributes"

Sure you can! Just add PolySharp and enable C# 11 😄

Note: as other mentioned, this scenario is not officially supported.

[tmds]

Great, thank you!

[pinkfloydx33]

I actually found myself in a similar situation... I really didn't care about net6.0, but wanted the net7.0 build to leverage required while I still need to multi-target my internal libraries. Only way I found around it was some nasty #ifdefs, enough so that I just gave up. I realize its not supported and I get that...but it'd be nice if it could somehow just be ignored

[saint4eva]

https://github.com/Sergio0694/PolySharp