Generic QuickSort in C#

Program.cs

using System;
using System.Collections.Generic;

class Program
{
    static void Main(string[] args)
    {
        var numbers = new int[] { 5, 4, 5, 7, 6, 9, 4, 1, 1, 3, 4, 50, 56, 41 };
        QuickSort(numbers);
        PrintList(numbers);
        Console.ReadKey();
    }

    private static void QuickSort<T>(T[] list) where T : IComparable
    {
        QuickSortInternal(list, 0, list.Length - 1);
    }

    private static void QuickSortInternal<T>(T[] list, int left, int right) where T : IComparable
    {
        if(left >= right)
        {
            return;
        }

        int partition = PartitionInternal(list, left, right);

        QuickSortInternal(list, left, partition - 1);
        QuickSortInternal(list, partition + 1, right);
    }

    private static int PartitionInternal<T>(T[] list, int left, int right) where T : IComparable
    {
        T partition = list[right];

        // stack items smaller than partition from left to right
        int swapIndex = left;
        for (int i = left; i < right; i++)
        {
            T item = list[i];
            if(item.CompareTo(partition) <= 0)
            {
                list[i] = list[swapIndex];
                list[swapIndex] = item;

                swapIndex++;
            }
        }

        // put the partition after all the smaller items
        list[right] = list[swapIndex];
        list[swapIndex] = partition;

        return right;
    }

    private static void PrintList<T>(IEnumerable<T> list)
    {
        foreach (var item in list)
        {
            Console.WriteLine(item);
        }
    }
}