using System;

using System.Collections.Generic;       

public class Program

{

    public struct Blep

    {

        public Blep(int d)

        {

            MyData =d;

        }

        public int MyData;

    }

    static void DoSomething(in Blep data)

    {

        Console.WriteLine($"Belp : {data.MyData}");

    }

    public static void Main()

    {

        List<Blep> datas = new()

        {

            new(1),

            new(2)

        };

​

        foreach(Blep b in datas)

        {

            DoSomething(b);

        }

    }

}