'static' in this context means 'checked at compile time' rather than 'restricted to a given set of values'.

However if restriction to given values is wanted, I'd suggest Hash::Utils as it is core in 5.8 and above (and it does the restriction natively rather than using tie). 

package Foo;
use strict;
use Hash::Util qw( lock_keys );

my @attrs = qw( name alias race );

sub new {
    my $class = shift;
    my %args = @_;

    my $self = bless {}, $class;
    lock_keys(%$self, @attrs);

    foreach my $k ( @attrs ) {
        if ( exists $args{$k} ) {
            $self->{$k} = $args{$k};
        }
    }
    return $self;
}

package main;

my $c = Foo->new(name => 'Aragorn', alias => 'Strider', race => 'Human
+');
print "name: $c->{name}\n"; 
print "job:  $c->{job}\n";

[download]
output: 
$ perl test.pl 
name: Aragorn
Attempt to access disallowed key 'job' in a restricted hash at test.pl
+ line 26.

[download]
As it happens, fields in 5.10 is implemented using Hash::Utils' restriction mechanism.

In reply to Re^4: Fields pragma - the poor man's OO framework? by Arunbear
in thread Fields pragma - the poor man's OO framework? by waba

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