From d56d12ca23d154c26490e6a4220afe0eea7b254a Mon Sep 17 00:00:00 2001
From: Oliver Booth <me@olivr.me>
Date: Fri, 31 Mar 2023 15:07:08 +0100
Subject: [PATCH] perf: lazily yield additional value

This prevents an allocation of the array, saving approximately half. Initial benchmarks also show this implementation to be ~100ns faster
---
 X10D/src/Linq/EnumerableExtensions.cs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/X10D/src/Linq/EnumerableExtensions.cs b/X10D/src/Linq/EnumerableExtensions.cs
index c94f10a..99b6773 100644
--- a/X10D/src/Linq/EnumerableExtensions.cs
+++ b/X10D/src/Linq/EnumerableExtensions.cs
@@ -31,7 +31,12 @@ public static class EnumerableExtensions
         }
 #endif
 
-        return source.Concat(new[] {value});
+        foreach (TSource item in source)
+        {
+            yield return item;
+        }
+
+        yield return value;
     }
 
     /// <summary>