deathly LINQ sample

HavingMaxByExtension.cs

using System;
using System.Collections.Generic;

namespace LinqTest
{
	public static class HavingMaxByExtension
	{
		private static TSource HavingMaxByInternal<TSource, TValue>(IEnumerable<TSource> source, Func<TSource, TValue> maxFunc)
			where TSource : class
			where TValue : struct, IComparable<TValue>
		{
			TSource maxItem = null;
			TValue? maxValue = null;
			
			foreach (var item in source)
			{
				TValue itemValue = maxFunc.Invoke(item);
				if (maxValue.HasValue == false || itemValue.CompareTo(maxValue.Value) >= 0) {
					maxItem = item;
					maxValue = itemValue;
				}
			}
			
			return maxItem;
		}

		public static TSource HavingMaxBy<TSource>(this IEnumerable<TSource> source, Func<TSource, int> maxFunc) where TSource : class
		{
			return HavingMaxByInternal(source, maxFunc);
		}

		public static TSource HavingMaxBy<TSource>(this IEnumerable<TSource> source, Func<TSource, float> maxFunc) where TSource : class
		{
			return HavingMaxByInternal(source, maxFunc);
		}
	}
}