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my $positive_number; tie $positive_number, "Enforcer", sub {$_[0] > 0}; $positive_number = 2; # ok $positive_number = 6.4; # ok $positive_number = -1; # croak!
my $x = 2; tie $x, "Enforcer", sub {...} # can Enforcer::TIESCALAR know that $x is currently 2??