       S : SequenceType
       where S.Generator.Element == Generator.Element
   >(newElements: S)
-}
 
-/// A collection type that can be efficiently appended-to.
-public protocol ExtensibleCollectionType : _ExtensibleCollectionType {
-/*
+  /*
   We could have these operators with default implementations, but the compiler
   crashes:
 

//
//===----------------------------------------------------------------------===//

/// This protocol is an implementation detail of `ExtensibleCollectionType`; do
/// not use it directly.
///
/// Its requirements are inherited by `ExtensibleCollectionType` and thus must
/// be satisfied by types conforming to that protocol.
public protocol _ExtensibleCollectionType : CollectionType {
  /// Create an empty instance.
  init()


}

public func +<
    C : ExtensibleCollectionType,
    S : CollectionType
    where S.Generator.Element == C.Generator.Element
>(var lhs: C, rhs: S) -> C {
