[stdlib] add span properties to array types

Author: glessard

stdlib/public/core/Array.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -1427,7 +1427,7 @@ extension Array: RangeReplaceableCollection {
       return try unsafe body(bufferPointer)
     }
   }
-
+  
   @inlinable
   public __consuming func _copyToContiguousArray() -> ContiguousArray<Element> {
     if let n = _buffer.requestNativeBuffer() {
@@ -1611,6 +1611,27 @@ extension Array {
     return try unsafe _buffer.withUnsafeBufferPointer(body)
   }
 
+  @available(SwiftStdlib 6.2, *)
+  public var span: Span<Element> {
+    @lifetime(borrow self)
+    @_alwaysEmitIntoClient
+    borrowing get {
+#if _runtime(_ObjC)
+      if _slowPath(!_buffer._isNative) {
+        let buffer = _buffer.getOrAllocateAssociatedObjectBuffer()
+        let pointer = unsafe buffer.firstElementAddress
+        let count = buffer.immutableCount
+        let span = unsafe Span(_unsafeStart: pointer, count: count)
+        return unsafe _overrideLifetime(span, borrowing: self)
+      }
+#endif
+      let pointer = unsafe _buffer.firstElementAddress
+      let count = _buffer.immutableCount
+      let span = unsafe Span(_unsafeStart: pointer, count: count)
+      return unsafe _overrideLifetime(span, borrowing: self)
+    }
+  }
+
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
   @_semantics("array.withUnsafeMutableBufferPointer")

stdlib/public/core/ArraySlice.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -1210,6 +1210,17 @@ extension ArraySlice {
     return try _buffer.withUnsafeBufferPointer(body)
   }
 
+  @available(SwiftStdlib 6.2, *)
+  public var span: Span<Element> {
+    @lifetime(borrow self)
+    @_alwaysEmitIntoClient
+    borrowing get {
+      let (pointer, count) = unsafe (_buffer.firstElementAddress, _buffer.count)
+      let span = unsafe Span(_unsafeStart: pointer, count: count)
+      return unsafe _overrideLifetime(span, borrowing: self)
+    }
+  }
+
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
   @_semantics("array.withUnsafeMutableBufferPointer")

stdlib/public/core/ContiguousArray.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -1152,6 +1152,18 @@ extension ContiguousArray {
     return try unsafe _buffer.withUnsafeBufferPointer(body)
   }
 
+  @available(SwiftStdlib 6.2, *)
+  public var span: Span<Element> {
+    @lifetime(borrow self)
+    @_alwaysEmitIntoClient
+    borrowing get {
+      let pointer = unsafe _buffer.firstElementAddress
+      let count = _buffer.immutableCount
+      let span = unsafe Span(_unsafeStart: pointer, count: count)
+      return unsafe _overrideLifetime(span, borrowing: self)
+    }
+  }
+
   // Superseded by the typed-throws version of this function, but retained
   // for ABI reasons.
   @_semantics("array.withUnsafeMutableBufferPointer")