Casting, Signatures & Return Types in rakudo

gistfile1.pl

multi sub to_num(Str $number) returns Num { +$number }
my $s = "10";
my $i = to_num($s);
say 'before: ' ~ $s.WHAT; # before: Str
say 'after : ' ~ $i.WHAT; # after : Num

=begin pod

=item Casting

Q: Is it currently possible to convert a Str to a Num e.g. the return value of prompt()?
A: Yes -- $number = +$string

=item Return types

Q: Should a sub/method/function complain if the return value does not match the specified type?
A: Yes -- Not implemented yet

=item Signatures

Q: Is the return type part of the signature and if not should it be?
A: Yes -- multi sub to_num(Str $s --> Num) { +$s }

=end pod