   /// Because of buffering, it is impossible to find the corresponding position
   /// in the generator for a given returned `UnicodeScalar` or an error.
   ///
-  /// - parameter next: A generator of code units to be decoded.
+  /// - Parameter next: A generator of code units to be decoded.  Repeated
+  /// calls to this method on the same instance should always reuse the same
+  /// generator.  Failing to do so will result in undefined behavior.
   public mutating func decode<
     G : GeneratorType where G.Element == CodeUnit
   >(input: inout G) -> UnicodeDecodingResult {

  /// Because of buffering, it is impossible to find the corresponding position
  /// in the generator for a given returned `UnicodeScalar` or an error.
  ///
  /// - parameter next: A generator of code units to be decoded.  Repeated
  /// calls to this method on the same instance should always reuse the same
  /// generator.  Failing to do so will result in undefined behavior.
  public mutating func decode<

  /// Because of buffering, it is impossible to find the corresponding position
  /// in the generator for a given returned `UnicodeScalar` or an error.
  ///
  /// - Parameter next: A generator of code units to be decoded.  Repeated
  /// calls to this method on the same instance should always reuse the same
  /// generator.  Failing to do so will result in undefined behavior.
  public mutating func decode<
    G : GeneratorType where G.Element == CodeUnit
  >(input: inout G) -> UnicodeDecodingResult {
