>perl -e"use diagnostics; use strict; print ${'x'}"
Can't use string ("x") as a SCALAR ref while "strict refs" in use at -e line 1 (#1)
    (F) Only hard references are allowed by "strict refs".  Symbolic
    references are disallowed.  See perlref.

Uncaught exception from user code:
        Can't use string ("x") as a SCALAR ref while "strict refs" in use at -e line 1.
 at -e line 1