One argument enumerable deconstruct

Author: andrewvk

CodeJam.Main/CodeJam.Main.csproj

@@ -128,6 +128,7 @@
 		<Compile Update="Collections\Enumerable\EnumerableExtensions.Deconstruct.generated.cs">
 			<AutoGen>True</AutoGen>
 			<DependentUpon>EnumerableExtensions.Deconstruct.tt</DependentUpon>
+			<DesignTime>True</DesignTime>
 		</Compile>
 		<Compile Update="Dates\DateTimeCode.generated.cs">
 			<AutoGen>True</AutoGen>

CodeJam.Main/Collections/Enumerable/EnumerableExtensions.Deconstruct.generated.cs

@@ -19,6 +19,49 @@ partial class EnumerableExtensions
 		private const string _listTooShortMsg = "The list is too short.";
 		private const string _enumTooShortMsg = "The enumerable is too short.";
 
+		/// <summary>
+		/// Deconstructs 1 item of the <paramref name="array"/>.
+		/// </summary>
+		[Pure]
+		public static void Deconstruct<T>(
+			[NotNull] this T[] array,
+			out T item1)
+		{
+			Code.NotNull(array, nameof (array));
+			Code.AssertArgument(array.Length >= 1, nameof (array), _arrayTooShortMsg);
+
+			item1 = array[0];
+		}
+
+		/// <summary>
+		/// Deconstructs 1 items of the <paramref name="list"/>.
+		/// </summary>
+		[Pure]
+		public static void Deconstruct<T>(
+			[NotNull] this IList<T> list,
+			out T item1)
+		{
+			Code.NotNull(list, nameof (list));
+			Code.AssertArgument(list.Count >= 1, nameof (list), _listTooShortMsg);
+
+			item1 = list[0];
+		}
+
+		/// <summary>
+		/// Deconstructs 1 items of the <paramref name="enumerable"/>.
+		/// </summary>
+		[Pure]
+		public static void Deconstruct<T>(
+			[NotNull] this IEnumerable<T> enumerable,
+			out T item1)
+		{
+			Code.NotNull(enumerable, nameof (enumerable));
+
+			using var enumerator = enumerable.GetEnumerator();
+			Code.AssertArgument(enumerator.MoveNext(), nameof (enumerable), _enumTooShortMsg);
+			item1 = enumerator.Current;
+		}
+
 		/// <summary>
 		/// Deconstructs 2 items of the <paramref name="array"/>.
 		/// </summary>

CodeJam.Main/Collections/Enumerable/EnumerableExtensions.Deconstruct.tt

@@ -13,15 +13,15 @@ namespace CodeJam.Collections
 		private const string _enumTooShortMsg = "The enumerable is too short.";
 
 <#
-	for (var i = 2; i <= 10; i++)
+	for (var i = 1; i <= 10; i++)
 		WriteDeconstructMethod(i);
 #>
 	}
 }
 
 <#+ private void WriteDeconstructMethod(int numOfParams) {#>
 		/// <summary>
-		/// Deconstructs <#=numOfParams#> items of the <paramref name="array"/>.
+		/// Deconstructs <#=numOfParams#> item<#=numOfParams > 1 ? "s" : ""#> of the <paramref name="array"/>.
 		/// </summary>
 		[Pure]
 		public static void Deconstruct<T>(