from S03: http://perlcabal.org/syn/S03.html#Conditional_operator_precedence
: It is a syntax error to use an operator in the middle part that binds looser in precedence, such as =. : my $x; : hmm() ?? $x = 1 !! $x = 2; # ERROR : hmm() ?? ($x = 1) !! ($x = 2); # works
