Overloading in Perl / Using overload.pm

overload::constant

• my %_const_handlers =
    (q => sub { 
            return __PACKAGE__->new($_[0]) 
               || $_[1] 
          });
  
  sub import {
    overload::constant %_const_handlers 
      if $_[1] eq ':constants';
  }
  
  sub unimport {
    overload::remove_constant(q => undef);
  }