package ClassPrintable;
use overload q{""} => sub { return shift->stringify() };

sub new {
  my ($class,$args) = @_;
  return bless($args,$class);
}

sub stringify {
  my $self = shift;
  my $ret = "{";
  for (sort keys %$self){
    $ret .= " $_ : ".$self->{$_}.",";
  }
  chop($ret) if (keys %$self);
  return "$ret".' }';
}

package main;

my $c = ClassPrintable->new({a =>1,b=>2,c=>3});
print $c;