use strict;
use warnings;

use Inline C => Config =>
  BUILD_NOISY => 1,
  PRE_HEAD => "#define PERL_NO_GET_CONTEXT",
  ;

use Inline C => <<'EOC';

SV * dubble(SV * in) {
 dTHX;
 return newSViv(SvIV(in) * 2);
}

EOC

my $x = dubble(23);
print $x; # 46