filename-example-2.p6

use v6;

class Filename is Str {
    # Do some filename type stuff, here...
}

sub MAIN(
    :$foo is copy where { $foo = Filename.new: :value($foo) }
    #= A filename argument.
  ) {
    say $foo.IO.basename;
}

# The monkey-typing version follows:

# use MONKEY-TYPING;

# class Filename is Str {
#     # Do some filename type stuff, here...
# }

# augment class Str { method Filename(Str:D:) { Filename.new(:value(self)) } }

# sub MAIN(
#     Filename(Str) :$foo
#     #= A filename argument.
#   ) {
#     say $foo.IO.basename;
# }