Collection Expression Arguments in C# 15 are "out"

The first preview of .NET 11 and C# 15 did just release. Some weeks back I did add already an article about that: "Collection Expression Arguments in C# 15+". Well quicker than anticipated that feature is now part of it!

Slightly different syntax

To my original blog post they changed the syntax.

Here the "pseudo" syntax used in the GitHub issue:

List<int> allNumbers = [args(capacity: 32), 0, ..evenNumbers, ..oddNumbers];

And here the final version:

List<int> allNumbers = [with(capacity: 32), 0, ..evenNumbers, ..oddNumbers];

They reused the with operator.

Resources

• More info also here: https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-15#collection-expression-arguments