StackLite<T> -TizzyT

using System;
using System.Collections;

public struct StackLite<T>
{
    internal readonly T _Value;
    internal readonly object _Next;

    public StackLite(T Value)
    {
        _Value = Value;
        _Next = default(StackLite<T>);
    }

    internal StackLite(T Value, StackLite<T> Next)
    {
        _Value = Value;
        _Next = Next;
    }
}

public static class StackLiteEx
{
    public static void Push<T>(ref this StackLite<T> @this, T value) => @this = new StackLite<T>(value, @this);

    public static T Peek<T>(ref this StackLite<T> @this)
    {
        if (@this.Equals(default(StackLite<T>))) throw new Exception("Stack is empty.");
        return @this._Value;
    }

    public static T Pop<T>(ref this StackLite<T> @this)
    {
        if (@this.Equals(default(StackLite<T>))) throw new Exception("Stack is empty.");
        T ret = @this._Value;
        @this = (StackLite<T>)@this._Next;
        return ret;
    }

    public static bool TryPeek<T>(ref this StackLite<T> @this, out T Value)
    {
        if (@this.Equals(default(StackLite<T>)))
        {
            Value = default;
            return false;
        }
        else
        {
            Value = @this._Value;
            return true;
        }
    }

    public static bool TryPop<T>(ref this StackLite<T> @this, out T Value)
    {
        if (@this.Equals(default(StackLite<T>)))
        {
            Value = default;
            return false;
        }
        else
        {
            Value = @this._Value;
            @this = (StackLite<T>)@this._Next;
            return true;
        }
    }
}