using System;

​

public struct Bla<T> {

    T[] data;

    public Bla(int count) {

        data = new T[count];

    }

    public static ref T Get(ref Bla<T> bla, int index) { return ref bla.data[index]; }

    public static ref readonly T GetConst(in Bla<T> bla, int index) { return ref bla.data[index]; }

    // imagine the rest

}

public static class BlaExtensions {

    public static ref T Get<T>(ref this Bla<T> bla, int index) { return ref Bla<T>.Get(ref bla, index); }

    public static ref readonly T GetConst<T>(in this Bla<T> bla, int index) { return ref Bla<T>.GetConst(bla, index); }

    // imagine the rest

}

​

public class Program

{

    public static void Main()

    {

        var x = new Bla<int>(5);

        x.Get(0) = 1;

        x.Get(1) = 2;

        x.Get(2) = 4;

        x.Get(3) = 8;

        x.Get(4) = 16;

        // x.GetConst(0) = 32; error

        var y = new Bla<Bla<int>>(1);

        y.Get(0) = new Bla<int>(1);

        y.Get(0).Get(0) = 32;

        // y.Get(0).GetConst(1) = 32; error

        // y.GetConst(0).Get(0) = 32; also error, see how i cant use the non-const thingy on the const thingy

    }

}