Why does C# disallow readonly local variables?

Question

Having a friendly debate with a co-worker about this. We have some thoughts about this, but wondering what the SO crowd thinks about this?

Answer 1

I know, this doesn't answer the why to your question. Anyway, those reading this question might appreciate the code below nonetheless.

If you are really concerned with shooting your self in the foot when overriding a local variable that should only be set once, and you don't want to make it a more globally accessible variable, you could do something like this.

    public class ReadOnly
    {
        public T Value { get; private set; }

        public ReadOnly(T pValue)
        {
            Value = pValue;
        }

        public static bool operator ==(ReadOnly pReadOnlyT, T pT)
        {
            if (object.ReferenceEquals(pReadOnlyT, null))
            {
                return object.ReferenceEquals(pT, null);
            }
            return (pReadOnlyT.Value.Equals(pT));
        }

        public static bool operator !=(ReadOnly pReadOnlyT, T pT)
        {
            return !(pReadOnlyT == pT);
        }
    }

Example usage:

        var rInt = new ReadOnly(5);
        if (rInt == 5)
        {
            //Int is 5 indeed
        }
        var copyValueOfInt = rInt.Value;
        //rInt.Value = 6; //Doesn't compile, setter is private

Maybe not as less code as rvar rInt = 5 but it works.