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