Re-add debug-mode overflow check in index(_:,_offsetBy:limit:)

lorentey · web-flow · commit 0a82ef8e13e9 · 2022-02-03T11:40:41.000-08:00
diff --git a/stdlib/public/core/UnsafeBufferPointer.swift.gyb b/stdlib/public/core/UnsafeBufferPointer.swift.gyb
@@ -221,8 +221,9 @@ extension Unsafe${Mutable}BufferPointer: ${Mutable}Collection, RandomAccessColle
       return nil
     }
 
-    // No need to check here, for the same index misuse reasons.
-    return i &+ n
+    let result = i.addingReportingOverflow(n)
+    _debugPrecondition(!result.overflow)
+    return result.partialValue
   }
 
   @inlinable // unsafe-performance

Original file line number	Diff line number	Diff line change
`@@ -221,8 +221,9 @@ extension Unsafe${Mutable}BufferPointer: ${Mutable}Collection, RandomAccessColle`
`221`	`221`	`return nil`
`222`	`222`	`}`
`223`	`223`
`224`		`- // No need to check here, for the same index misuse reasons.`
`225`		`- return i &+ n`
	`224`	`+ let result = i.addingReportingOverflow(n)`
	`225`	`+ _debugPrecondition(!result.overflow)`
	`226`	`+ return result.partialValue`
`226`	`227`	`}`
`227`	`228`
`228`	`229`	`@inlinable // unsafe-performance`