The following code works for me (in teh sense that Object::InsideOut doesn't immediately complain):

#!/usr/bin/perl

package CodeRef; 
use strict;
{
    use Object::InsideOut;

warn sprintf "Using %s version %s", 
    'Object::InsideOut::VERSION',
    $Object::InsideOut::VERSION
    ;

  my @code :Field
           :Std( Name => 'code', Private => 1 )
           :Arg(Name => 'code', Mand =>1 )
           :Type(CODE);

sub call() {
    my $self = shift;
    my $code = $self->get_code();
    return $code->(@_);
  }

}

1;

#=====

package main;

sub sum {
  my $sum =0 ;
  foreach my $num (@_) {
    $sum += $num;
}
  return $sum;
}

my $cref = CodeRef->new( code => \&sum );

__END__

Using Object::InsideOut::VERSION version 3.81 at tmp.pl line 9.
[download]