Definitely not C#. Wrong syntax for main, wrong syntax for foreach (C# has foreach (var i in someCollection) and what even is this method call syntax with =?

Edit: I dug around the website. It’s D. I’m still confused about the method call syntax though. Usually, D uses parentheses like most other C-style languages. Must be some weird syntax where you can call methods like property setters which was useful for this particular code golf challenge.