Re: How check if expression has a type without triggering compilation failure

[cdome]

I need something that not going to cause compilation error for the case when 
expr does not have a type
    
    
    template filter(expr: untyped) =
      when expr is seq[bool]: echo "bool"
      elif expr is seq[int]:  echo "int"
      else:                   discard
    
    filter(a + b)  # a and b are not defined, hence no type.
                   # Should gracefully go to else statement, but currently 
causes compilation error