   public static func transcodedLength<
     Encoding : UnicodeCodec, Input : IteratorProtocol
     where Encoding.CodeUnit == Input.Element
-    >(
+  >(
     of input: Input,
     decodedAs sourceEncoding: Encoding.Type,
     repairingIllFormedSequences: Bool
-    ) -> (count: Int, isASCII: Bool)? {
-      var input = input
-      var count = 0
-      var isAscii = true
-
-      var inputDecoder = Encoding()
-      loop:
-        while true {
-          switch inputDecoder.decode(&input) {
-          case .scalarValue(let us):
-            if us.value > 0x7f {
-              isAscii = false
-            }
-            count += width(us)
-          case .emptyInput:
-            break loop
-          case .error:
-            if !repairingIllFormedSequences {
-              return nil
-            }
-            isAscii = false
-            count += width(UnicodeScalar(0xfffd))
-          }
-      }
-      return (count, isAscii)
+  ) -> (count: Int, isASCII: Bool)? {
+    var input = input
+    var count = 0
+    var isAscii = true
+
+    var inputDecoder = Encoding()
+    loop:
+    while true {
+      switch inputDecoder.decode(&input) {
+      case .scalarValue(let us):
+        if us.value > 0x7f {
+          isAscii = false
+        }
+        count += width(us)
+      case .emptyInput:
+        break loop
+      case .error:
+        if !repairingIllFormedSequences {
+          return nil
+        }
+        isAscii = false
+        count += width(UnicodeScalar(0xfffd))
+      }
+    }
+    return (count, isAscii)
   }
 }
 

    return UTF8.CodeUnit(utf16)
  }
}
extension UTF16 {
  /// Returns the number of code units required to encode `x`.
  @warn_unused_result

    _precondition(width(x) == 2)
    return UTF16.CodeUnit(
      (x.value - 0x1_0000) & (((1 as UInt32) << 10) - 1)
    ) + 0xDC00
  }

  @warn_unused_result
