Question

I would like to know whether the following statements are same or different

1> catch (domain_error const & x) 
2> catch (const domain_error & x)
3> catch (domain_error & const x) // I think this is illegal

Basically, I thought case 1> and case 2> are same and case 3> is not legal syntax.
Please correct me if I am wrong.

Answer 1

You are correct; the first two are equivalent and the last one is an error.

More generally, when dealing with references, the syntaxes

const T&

and

T const &

are equivalent, while

T & const

is not allowed.