doom's explanation is wrong. It has nothing to do with order. Even if you fixed the order, it still wouldn't work.

(my $t = shift) and print $t;   # Fails.
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Variables cannot be used (by name) in the statement in which they are declared. This allows statements such as my $t = $t; to work.

print $t if (my $t = shift);       # Fails.
my $t = shift; print $t if $t;     # Ok.
if (my $t = shift) { print $t; }   # Ok.
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