{
use MCE::Shared;

my $cnt; 

#tie my $cnt, 'MCE::Shared', { module => 'MCE::Shared::Scalar' }, 0;

tie my $va1, 'MCE::Shared', { module => 'MCE::Shared::Scalar' }, sub { return $cnt++; }; #just for fun let's make a closure 

# How can I be sure that ($val->() == 0)?

say ($val->()) ? 0 : 1;  # says 1 if first caller

}