Array-copy in Peek is not necessary, JIT can do the same

gfoidl · gfoidl · commit b0bfd83db525 · 2017-12-29T17:17:02.000+01:00
As of PR-feedback #26086 (comment)
diff --git a/src/System.Collections/src/System/Collections/Generic/Stack.cs b/src/System.Collections/src/System/Collections/Generic/Stack.cs
@@ -203,14 +203,13 @@ public void TrimExcess()
         public T Peek()
         {
             int size = _size - 1;
-            T[] array = _array;
 
-            if ((uint)size >= (uint)array.Length)
+            if ((uint)size >= (uint)_array.Length)
             {
                 ThrowForEmptyStack();
             }
             
-            return array[size];
+            return _array[size];
         }
 
         public bool TryPeek(out T result)

Original file line number	Diff line number	Diff line change
`@@ -203,14 +203,13 @@ public void TrimExcess()`
`203`	`203`	`public T Peek()`
`204`	`204`	`{`
`205`	`205`	`int size = _size - 1;`
`206`		`- T[] array = _array;`
`207`	`206`
`208`		`- if ((uint)size >= (uint)array.Length)`
	`207`	`+ if ((uint)size >= (uint)_array.Length)`
`209`	`208`	`{`
`210`	`209`	`ThrowForEmptyStack();`
`211`	`210`	`}`
`212`	`211`
`213`		`- return array[size];`
	`212`	`+ return _array[size];`
`214`	`213`	`}`
`215`	`214`
`216`	`215`	`public bool TryPeek(out T result)`