Define a primitive data type: Difference between revisions

=={{header|Perl 6}}==

{{works with|Rakudo|#22 "Thousand Oaks"}}

<lang perl>subset OneToTen of Int where 1 <= * <= 10;

my OneToTen $n = 5;

$n += 6;</lang>

<code>(1 <= * <= 10)(11)</code> returns a false value, so the second assignment throws an exception. You can use any unary function in place of <code>1 <= * <= 10</code>, so this, for example, is also legal:

<lang perl>subset Prime of Int where { $^n > 1 and $^n !% none 2 .. sqrt $^n }</lang>