perl -wMstrict -e "$::x=0; $x++"                        # not OK
perl -wMstrict -e "package foo; $foo::x=0; $x++"        # not OK

##</code><code>##

perl -wMstrict -e "BEGIN{*::x=\$a} $x++"                # not OK (1)
perl -wMstrict -e "BEGIN{package foo; *::x=\$a} $x++"   # OK     (2)

##</code><code>##

perl -wMstrict -e "{package foo; *::x=\$a} $x++"        # not OK

##</code><code>##

C:\>perl -MO=Deparse -wMstrict -e "{package foo; *::x=\$a} $x++"
Variable "$x" is not imported at -e line 1.
Global symbol "$x" requires explicit package name (did you forget to declare "my
 $x"?) at -e line 1.
-e had compilation errors.
BEGIN { $^W = 1; }
use strict;
{
    package foo;
    *main::x = \$a;
}
$main::x++;

##</code><code>##

perl -wMstrict -e "BEGIN{package bar; *bar::x=\$a} package bar; $x++"   # not OK
perl -wMstrict -e "BEGIN{package foo; *bar::x=\$a} package bar; $x++"   # OK