help.c

#include <stdlib.h>

struct TODD {
  int x;
};

struct TODD * parray(int n) {
  int sz = sizeof(size_t);
  struct TODD *ts = malloc(n*sz);
  for(int i=0; i<n; i++){
    ts[i].x = i;
  }
  return ts;
}

# gcc -shared -ohelp.so help.c

help.raku

use NativeCall;

class TODD is repr('CStruct') {
  has int32 $.x;
}

sub parray(int32) returns Pointer is native('./help.so') {*}

my $head = parray(10);

(0..^10).map(-> $i {
  say nativecast(
    TODD,
    Pointer.new($head + ($i * nativesizeof(TODD))),
  ).x;
});

# must be run in same dir as help.c or you must correct the path on line 7