Powershell: Obsolete struct System.Span was introduced

[TravisEz13]

https://docs.microsoft.com/en-us/dotnet/api/system.span-1?view=netcore-2.0

It was introduced by this change:
https://github.com/PowerShell/PowerShell/pull/6504

[daxian-dbw]

/cc @iSazonov @SteveL-MSFT

[SteveL-MSFT]

That doc seems to be wrong. Span is new and isn’t marked obsolete in corefx https://github.com/dotnet/corefx/blob/master/src/System.Memory/src/System/Span.Portable.cs. We would have a compilation error if it was obsolete

[iSazonov]

It is in runtime and System.Memory from last summary.

[iSazonov]

I found description of the feature https://github.com/dotnet/csharplang/blob/master/proposals/csharp-7.2/span-safety.md#metadata-representation-or-ref-like-structs

Having no other good alternatives that work in old compilers without servicing, an Obsolete attribute with a known string will be added to all ref-like structs. Compilers that know how to use ref-like types will ignore this particular form of Obsolete.

[daxian-dbw]

Thanks @iSazonov, that explains it :)

[TravisEz13]

Once I did a second restore this error went away. VS seemed to have some issues...