I don't think this works in Perl 5, the variable is only visible in the statement after the declaration. It works in Perl 6, though: 
$ perl6 -e 'sub f { 3 }; sub g($a) { $a }; if my $x = f() and g($x) { 
+say "works" }'
works

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In reply to Re: scope of my $x in if statements by moritz
in thread scope of my $x in if statements by perl5ever

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