anchor.diff:  
   /// Read a string from [input].
   String readNativeString(input) {
  +  _ensure();
     if (input is String) {
       return input;
     }
  
positive.code: 
  /// Allocate an object specified by [type] using the initial value specified by [value].
  BinaryData alloc(type, [value]) {
    BinaryType bt = _getBinaryType(type);
    return bt.alloc(value);
  }
  
negative.code: #endif
  """;
  
  void _ensure() {
    if (LibC._libc == null) {
      LibC.load();
    }
  }
  
  /// C Library
  class LibC {
    static BinaryTypeHelper typeHelper;
  
    static BinaryTypes get types => libc.types;
  
    static DynamicLibrary _libc;
    static DynamicLibrary get libc {
  