anchor.diff:  	assert(s.count('_') == 0u);
   	assert(s.last == '\0');
   	assert(s.first == '\0');
  +	assert(s.data == null);
   
   	s << "";
   	assert(s.size == 0u);
  
positive.code: 	assert(s.count('_') == 0u);
  	assert(s.last == '\0');
  	assert(s.first == '\0');
  
  	s.clear();
  	assert(s.size == 0u);
  
negative.code: 	assert(s.count('o') == 1u);
  	assert(s.last == 'o');
  	assert(s.first == 'h');
  	assert(s.data != null);
  
  	s += " world !";
  	assert(s.capacity >= 13u);
  