Just tried this simple script:

use strict;
use warnings;

my (%info, $quack);

# If this is commented out, "no quack"
$info{baz} = 3;

# Assignment intentional in conditional
if ($quack = $info{foo} or $quack = $info{bar} or $quack = $info{baz})
+ {
    print "Quack is $quack\n";
}
else {
    print "No quack\n";
}
[download]

Prints "Quack is 3".