Adding TryLast extension methods

ICD.Common.Utils.Tests/Extensions/EnumerableExtensionsTest.cs

@@ -3,7 +3,6 @@ using ICD.Common.Utils.Extensions;
 using NUnit.Framework;
 using System.Collections.Generic;
 using System.Linq;
-using System;
 
 namespace ICD.Common.Utils.Tests.Extensions
 {
@@ -62,6 +61,41 @@ namespace ICD.Common.Utils.Tests.Extensions
 			Assert.AreEqual(true, exists);
 		}
 
+		[TestCase(1)]
+		public void TryLastTest(int expected)
+		{
+			IEnumerable<int> sequence = Enumerable.Empty<int>();
+			int result;
+			bool exists = sequence.TryLast(out result);
+
+			Assert.AreEqual(0, result);
+			Assert.AreEqual(false, exists);
+
+			sequence = new[] { expected };
+			exists = sequence.TryLast(out result);
+
+			Assert.AreEqual(expected, result);
+			Assert.AreEqual(true, exists);
+		}
+
+		[TestCase(0)]
+		[TestCase(1)]
+		public void TryLastPredicateTest(int expected)
+		{
+			IEnumerable<int> sequence = Enumerable.Range(1, 10).Except(expected);
+			int result;
+			bool exists = sequence.TryLast(i => i == expected, out result);
+
+			Assert.AreEqual(0, result);
+			Assert.AreEqual(false, exists);
+
+			sequence = new[] { expected };
+			exists = sequence.TryLast(i => i == expected, out result);
+
+			Assert.AreEqual(expected, result);
+			Assert.AreEqual(true, exists);
+		}
+
 		[TestCase(0, 0)]
 		[TestCase(1, 10)]
 		public void TryElementAtTest(int index, int expected)

ICD.Common.Utils/Extensions/EnumerableExtensions.cs

@@ -94,6 +94,55 @@ namespace ICD.Common.Utils.Extensions
 			return false;
 		}
 
+		/// <summary>
+		/// Returns true if there is at least 1 item in the sequence.
+		/// </summary>
+		/// <typeparam name="T"></typeparam>
+		/// <param name="extends"></param>
+		/// <param name="item">Outputs the last item in the sequence.</param>
+		/// <returns></returns>
+		public static bool TryLast<T>(this IEnumerable<T> extends, out T item)
+		{
+			if (extends == null)
+				throw new ArgumentNullException("extends");
+
+			return extends.TryLast(i => true, out item);
+		}
+
+		/// <summary>
+		/// Returns true if there is at least 1 item in the sequence.
+		/// </summary>
+		/// <typeparam name="T"></typeparam>
+		/// <param name="extends"></param>
+		/// <param name="predicate"></param>
+		/// <param name="item">Outputs the last item in the sequence.</param>
+		/// <returns></returns>
+		public static bool TryLast<T>(this IEnumerable<T> extends, Func<T, bool> predicate, out T item)
+		{
+			if (extends == null)
+				throw new ArgumentNullException("extends");
+
+			if (predicate == null)
+				throw new ArgumentNullException("predicate");
+
+			item = default(T);
+			bool output = false;
+
+			using (IEnumerator<T> iterator = extends.GetEnumerator())
+			{
+				while (iterator.MoveNext())
+				{
+					if (!predicate(iterator.Current))
+						continue;
+
+					item = iterator.Current;
+					output = true;
+				}
+			}
+
+			return output;
+		}
+
 		/// <summary>
 		/// Returns the true if an element with the given index is in the sequence.
 		/// </summary>