func: QString *qstring_from_substr(const char *str, int start, int end)
  
  {
  
      QString *qstring;
  
  
  
      qstring = g_malloc(sizeof(*qstring));
  
  
  
      qstring->length = end - start + 1;
  
      qstring->capacity = qstring->length;
  
  
  
      qstring->string = g_malloc(qstring->capacity + 1);
  
      memcpy(qstring->string, str + start, qstring->length);
  
      qstring->string[qstring->length] = 0;
  
  
  
      QOBJECT_INIT(qstring, &qstring_type);
  
  
  
      return qstring;
  
  }
  