Install libperlx-maybe-perl by entering the following commands in the terminal:
sudo apt update sudo apt install libperlx-maybe-perl
return a pair only if they are both defined
Moose classes (and some other classes) distinguish between an attribute being unset and the attribute being set to undef. Supplying a constructor arguments like this: . my $bob = Person->new( name => $name, age => $age, ); . Will result in the "name" and "age" attributes possibly being set to undef (if the corresponding $name and $age variables are not defined), which may violate the Person class' type constraints. . PerlX::Maybe checks that $x and $y are both defined. If they are, it returns them both as a list; otherwise it returns the empty list. . This package also includes Syntax::Feature::Maybe.