Native int postcircumifx:<[ ]>

01.patch

diff --git a/src/core/Any.pm b/src/core/Any.pm
index a0476f6..d5399b5 100644
--- a/src/core/Any.pm
+++ b/src/core/Any.pm
@@ -112,6 +112,10 @@ my class Any {
         fail "Cannot use negative index $pos on {self.WHAT.perl}" if $pos < 0;
         self.at_pos($pos)
     }
+    multi method postcircumfix:<[ ]>(int $pos) is rw {
+        fail "Cannot use negative index $pos on {self.WHAT.perl}" if $pos < 0;
+        self.at_pos($pos)
+    }
     multi method postcircumfix:<[ ]>(Positional $pos) is rw {
         my $list = $pos.flat;
         $list.gimme(*);
diff --git a/src/core/List.pm b/src/core/List.pm
index d4f975f..a944873 100644
--- a/src/core/List.pm
+++ b/src/core/List.pm
@@ -47,12 +47,18 @@ my class List does Positional {
         nqp::p6parcel($rpa, Any);
     }
 
-    method at_pos($pos is copy) is rw {
+    proto method at_pos($) { * }
+    multi method at_pos($pos is copy) is rw {
         $pos = $pos.Int;
         self.exists($pos)
           ?? nqp::atpos($!items, nqp::unbox_i($pos))
           !! Nil
     }
+    multi method at_pos(int $pos) is rw {
+        self.exists($pos)
+            ?? nqp::atpos($!items, $pos)
+            !! Nil;
+    }
 
     method eager() { self.gimme(*); self }
 

02-bench.pl

my @a = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
loop (my int $i = 0; $i < 10_000; $i = $i + 1) {
    loop (my int $j = 0; $j < 10; $j = $j + 1) {
       eager @a[$j];
    }
}

03-analyze.pl

my @patched  = (26.470, 26.127, 26.235, 25.836, 26.133);
my @original = (26.265, 25.648, 26.745, 26.045, 26.805);

sub avg(*@a) {
    ([+] @a) / @a.elems;
}

sub std(*@a) {
    sqrt( avg(@a X** 2) - avg(@a) ** 2);
}

my $avg_p = avg @patched;
my $std_p = std @patched;
my $avg_o = avg @original;
my $std_o = std @original;

my $std = ($std_p + $std_o) / sqrt(2);
my $sigmas = abs($avg_p - $avg_o) / $std;

say "Original: $avg_o ± $std_o";
say "Patched:  $avg_p ± $std_p";
say ($avg_o < $avg_p) ?? 'original' !! 'patched',
    ' version is faster by ', $sigmas, 'σ';

04-result.txt

Original: 26.3016 ± 0.434601242520083
Patched:  26.1602 ± 0.20421498475871
patched version is faster by 0.313031806614212σ