30 

    31 

    32 

    33 

    34 elementary_type_c *elementary_type_c::singleton = NULL;

    35 

    36 const char *elementary_type_c::to_string(symbol_c *symbol) {

    37   if (NULL == singleton)    singleton = new elementary_type_c;

    38   if (NULL == singleton)    ERROR;

    39   const char *res           = (const char *)symbol->accept(*singleton);

    40   if (NULL == res)          ERROR;

    41   return res;

    42 }