gamma.raku

#!/usr/bin/env raku
use v6;

use NativeCall;

sub Γ(num64 --> num64) is native('m', v6) is symbol('tgamma') { * }
sub postfix:<!>(Num() $x) { Γ $x + 1 }
sub √(Num() $x) { $x.sqrt }

say ½!;
say √π ÷ 2;

use Test;

is-approx ½!, √π ÷ 2, "½! ≅ √π ÷ 2";

done-testing;