If Foundation is available, mark Buffer as ContiguousBytes

Useful in other contexts.

Sources/MacroCore/Buffer/BufferData.swift

@@ -3,12 +3,13 @@
 //  Macro
 //
 //  Created by Helge Heß.
-//  Copyright © 2020-2023 ZeeZide GmbH. All rights reserved.
+//  Copyright © 2020-2024 ZeeZide GmbH. All rights reserved.
 //
 
 #if canImport(Foundation)
 
-import struct Foundation.Data
+import struct   Foundation.Data
+import protocol Foundation.ContiguousBytes
 import NIOCore
 import NIOFoundationCompat
 
@@ -17,16 +18,32 @@ public extension Buffer {
   /**
    * Initialize the Buffer with the contents of the given `Data`. Copies the
    * bytes.
+   *
+   * - Parameters:
+   *   - data: The bytes to copy into the buffer.
    */
-  @inlinable init(_ data: Data) {
+  @inlinable
+  init(_ data: Data) {
     self.init(capacity: data.count)
     byteBuffer.writeBytes(data)
   }
 
-  @inlinable var data : Data {
+  @inlinable
+  var data : Data {
     return byteBuffer.getData(at     : byteBuffer.readerIndex,
                               length : byteBuffer.readableBytes) ?? Data()
   }
 }
 
+extension Buffer: ContiguousBytes {
+
+  @inlinable
+  public func withUnsafeBytes<R>(_ body: (UnsafeRawBufferPointer) throws -> R)
+    rethrows -> R
+  {
+    return try byteBuffer.readableBytesView.withUnsafeBytes(body)
+  }
+
+}
+
 #endif // canImport(Foundation)