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Collection expressions confusion
I'm trying out C# 12 with LINQPad 8.0.10 (x64), and the compiled output is confusing me.
VS2022 is telling me to replace every call to Array.Empty with the new collection expression sytnax:
T[] emptyArray = Array.Empty<T>(); // becomes: T[] emptyArray = [];
However, LINQPad's "C# 1" output, and the ILSpy output, shows that compiling to:
T[] emptyArray = new T[0];
which would obviously be sub-optimal.
This is regardless of the selected .NET version, and the state of the optimizations flag.
However, using SharpLab to examine the same code shows it correctly compiling to:
T[] emptyArray = Array.Empty<T>();
If I compile a test project in VS2022 with the same code, and then decompile it, I also see it calling Array.Empty.
Is there an obvious cause and/or fix for this confusion?
Comments
It's possible that this has been fixed in more recent Roslyn builds. LINQPad uses the latest stable Roslyn RTM, for which C# 12 is still technically in preview status. LINQPad will use the newer Roslyn assemblies as soon as they become available, which is usually around a week after a new .NET release.
This should be fixed in 8.0.12.
Excellent news! Thanks for the explanation, and the speedy update.