Use List for Memoize's cache (performance)

atifaziz · web-flow · commit ce7250fcae16 · 2018-11-15T09:21:42.000+01:00
Indexing into an IList<> requires an interface call, and can't be inlined. Since the cache field is private, there is no reason to not type it instead as List<>, thus get a free performance gain at no cost. Closes morelinq#546
diff --git a/MoreLinq/Experimental/Memoize.cs b/MoreLinq/Experimental/Memoize.cs
@@ -62,7 +62,7 @@ public static IEnumerable<T> Memoize<T>(this IEnumerable<T> source)
 
     sealed class MemoizedEnumerable<T> : IEnumerable<T>, IDisposable
     {
-        IList<T> _cache;
+        List<T> _cache;
         readonly object _locker;
         readonly IEnumerable<T> _source;
         IEnumerator<T> _sourceEnumerator;

Original file line number	Diff line number	Diff line change
`@@ -62,7 +62,7 @@ public static IEnumerable<T> Memoize<T>(this IEnumerable<T> source)`
`62`	`62`
`63`	`63`	`sealed class MemoizedEnumerable<T> : IEnumerable<T>, IDisposable`
`64`	`64`	`{`
`65`		`- IList<T> _cache;`
	`65`	`+ List<T> _cache;`
`66`	`66`	`readonly object _locker;`
`67`	`67`	`readonly IEnumerable<T> _source;`
`68`	`68`	`IEnumerator<T> _sourceEnumerator;`