use warnings;
use Inline C => Config =>
    BUILD_NOISY => 1;

use Inline C => <<'EOC';

void add_nir(int x, int y, SV * ref_int) {
     sv_setiv(ref_int, x + y);
}

EOC

my $test;
add_nir(1, 4, $test);
print $test, "\n"; # prints "5"