package main;
{
    no warnings 'once';
    *main::foo = sub {print "Foo\n"}
    foo();
}

##</code><code>##

package main;
sub foo {print "Foo\n"}

##</code><code>##

use strict;
use warnings;

my %classes = (
    student => {
        name    => [qw(get set)],
        id      => [qw(get set)],
    },
);

foreach my $class (keys %classes) {
    my $cname = ucfirst $class;
    $cname =~ s/_(\w)/uc $1/eg;
    my @data_members;
    foreach my $data_member (keys %{$classes{$class}}) {
        push @data_members, $data_member;
        foreach my $accessor (@{$classes{$class}{$data_member}}) {
            if ($accessor eq 'get') {
                no strict 'refs';
                no warnings 'once';
                print "creating sub ${cname}::${data_member}_get\n";
                *{$cname . '::' . $data_member . '_get'} = sub {my $self = shift; return $self->{$data_member}};
            }
            elsif ($accessor eq 'set') {
                no strict 'refs';
                no warnings 'once';
                print "creating sub ${cname}::${data_member}_set\n";
                *{$cname . '::' . $data_member . '_set'} = sub {my $self = shift; return $self->{$data_member} = shift};
            }
            else {
                die "Unrecognized accessor type: ${cname}::${data_member}_$accessor.\n";
            }
        }
    }
    {
        no strict 'refs';
        no warnings 'once';

        print "creating sub ${cname}::new with data members (@data_members)\n";
        *{$cname . '::' . 'new'} = sub {
            my ($class, $args)    = @_;
            my $self              = {};
            $self->{$_} = $args->{$_} for keys %$args;
            return bless $self, $class;
        };
    }
}

# Instantiate an object of class Student:
my $s = Student->new({name => 'John Doe', id => 1234});

print "\n\n";

# Use the 'get' accessors for an object of class Student:
print $s->id_get, ": ", $s->name_get, "\n";

# Use one of the 'set' accessors for the object:
$s->name_set('Mark Doe');

# Verify the change:
print $s->id_get, ": ", $s->name_get, "\n";

##</code><code>##

creating sub Student::name_get
creating sub Student::name_set
creating sub Student::id_get
creating sub Student::id_set
creating sub Student::new with data members (name id)


1234: John Doe
1234: Mark Doe