Useful for doing operation performance timing in C#.

using System;
using System.Diagnostics;

public class OperationTimer : IDisposable
{
    private Stopwatch _stopwatch;
    private String _text;
    private Int32 _collectionCount;

    public OperationTimer(String text)
    {
        PrepareForOperation();

        _text = text;
        _collectionCount = GC.CollectionCount(0);

        // This should be the last statement in this
        // method to keep timing as accurate as possible
        _stopwatch = Stopwatch.StartNew();
    }

    public void Dispose()
    {
        Console.WriteLine("{0} (GCs={1,3}) {2}", (_stopwatch.Elapsed),
                          GC.CollectionCount(0) - _collectionCount, _text);
    }

    private static void PrepareForOperation()
    {
        GC.Collect();
        GC.WaitForPendingFinalizers();
        GC.Collect();
    }
}

//
// Usage

public static void ValueTypePerfTest()
{
    const Int32 count = 100000000;

    using(new OperationTimer("List<Int32>"))
    {
        List<Int32> l = new List<Int32>();
        for (Int32 n = 0; n < count; n++)
        {
            l.Add(n);         // No boxing
            Int32 x = l[n];  // No unboxing
        }
        l = null;  // Make sure this gets GC'd
    }

    using(new OperationTimer("ArrayList of Int32"))
    {
        ArrayList a = new ArrayList();
        for (Int32 n = 0; n < count; n++)
        {
            a.Add(n);                // Boxing
            Int32 x = (Int32)a[n];  // Unboxing
        }
        a = null;  // Make sure this gets GC'd
    }
}

public static void ReferenceTypePerfTest()
{
    const Int32 count = 100000000;

    using(new OperationTimer("List<String>"))
    {
        List<String> l = new List<String>();
        for (Int32 n = 0; n < count; n++)
        {
            l.Add("X");           // Reference copy
            String x = l[n];      // Reference copy
        }
        l = null;  // Make sure this gets GC'd
    }

    using(new OperationTimer("ArrayList of String"))
    {
        ArrayList a = new ArrayList();
        for (Int32 n = 0; n < count; n++)
        {
            a.Add("X");                 // Reference copy
            String x = (String)a[n];  // Cast check & reference copy
        }
        a = null;  // Make sure this gets GC'd
    }
}