> Different types can [AFAIR] per the standard theoretically be in different address spaces
If you can force the types to contain a member of the same type (say, a int or enum foobar_discriminant), the pointers &const_var_foo.disc and &const_var_bar.disc would have to differ for obvious reasons.
If you can force the types to contain a member of the same type (say, a int or enum foobar_discriminant), the pointers &const_var_foo.disc and &const_var_bar.disc would have to differ for obvious reasons.