code: def is_binary_operator(oper):
      
      # definition:
      # member in class
      # ret-type operator symbol(arg)
      # globally
      # ret-type operator symbol( arg1, arg2 )
      symbols = [
          ',', '()', '[]', '!=', '%', '%=', '&', '&&', '&=', '*', '*=', '+',
          '+=', '-', '-=', '->', '->*', '/', '/=', '<', '<<', '<<=', '<=', '=',
          '==', '>', '>=', '>>', '>>=', '^', '^=', '|', '|=', '||']
      if not isinstance(oper, calldef_members.operator_t):
          return False
      if oper.symbol not in symbols:
          return False
  
      if isinstance(oper, calldef_members.member_operator_t):
          if len(oper.arguments) == 1:
              return True
          return False
  
      if len(oper.arguments) == 2:
          return True
      return False
docs: returns True, if operator is binary operator, otherwise False