Ternary Operator with Subroutine

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

When I run this code, it complains that

"Useless use of reference constructor in void context."

Can someone tell me what is going on?

#!/usr/bin/perl

use strict;
use warnings;

( my $test ) 
  ? print 'c'
  : sub { print 'a'; print 'b' }
[download]

On the other hand, this works.

#!/usr/bin/perl

use strict;
use warnings;

( my $test )
  ? print 'c'
  : print_me();

sub print_me {
    print 'a';
    print 'b';
}
[download]