[stdlib] Reorder increment and element creation to not need (#5062)

Nicholas Maccharoli · moiseev · commit 3d7f8cc1a00f · 2016-10-14T14:05:49.000-07:00
diff --git a/stdlib/public/core/Algorithm.swift b/stdlib/public/core/Algorithm.swift
@@ -106,8 +106,9 @@ public struct EnumeratedIterator<
   /// Once `nil` has been returned, all subsequent calls return `nil`.
   public mutating func next() -> Element? {
     guard let b = _base.next() else { return nil }
-    defer { _count += 1 }
-    return (offset: _count, element: b)
+    let result = (offset: _count, element: b)
+    _count += 1 
+    return result
   }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -106,8 +106,9 @@ public struct EnumeratedIterator<`
`106`	`106`	/// Once `nil` has been returned, all subsequent calls return `nil`.
`107`	`107`	`public mutating func next() -> Element? {`
`108`	`108`	`guard let b = _base.next() else { return nil }`
`109`		`- defer { _count += 1 }`
`110`		`- return (offset: _count, element: b)`
	`109`	`+ let result = (offset: _count, element: b)`
	`110`	`+ _count += 1`
	`111`	`+ return result`
`111`	`112`	`}`
`112`	`113`	`}`
`113`	`114`