package CSLocal;
use strict;
use base qw/Class::Singleton/;
my @value_stack = ();
sub undefine_value { delete $_[0]->{VALUE}; }
sub value {
        my $self = shift;
        $self->{VALUE} = $_[0] if @_;
        $self->{VALUE};
}
sub localize {
        my $self = shift;
        push @value_stack, $self->value ();
        $self->undefine_value ();
}
sub restore {
        my $self = shift;
        die "no values to restore" unless @value_stack;
        my $val = pop @value_stack;
        $self->value ($val);
}
1;