デストラクタ

デストラクタがあることに少しびっくりした。
参照カウンタの成せる技かな。

#!/usr/bin/env perl
use warnings;
use strict;
use Carp;

package Foo;

sub new {
  my ($class, $x) = @_;
  print "Foo::new($x)" . "\n";
  bless { x => $x }, $class;
}

sub func {
  my $self = shift;
  print "Foo($self->{x})->func()\n";
}

sub DESTROY {
  my $self = shift;
  print "Foo($self->{x})->DESTROY()" . "\n";
}

package main;

my $a = new Foo(1);
#my $x;

print "----- scope in  -----\n";
{
  my $b = new Foo(2);
  $b->func();
  #$x = $b;
}
print "----- scope out -----\n";

$a->func();

Foo::new(1)

----- scope in  -----

Foo::new(2)

Foo(2)->func()

Foo(2)->DESTROY()

----- scope out -----

Foo(1)->func()

Foo(1)->DESTROY()

#!/usr/bin/env perl
use warnings;
use strict;
use Carp;

package Foo;

sub new {
  my ($class, $x) = @_;
  print "Foo::new($x)" . "\n";
  bless { x => $x }, $class;
}

sub func {
  my $self = shift;
  print "Foo($self->{x})->func()\n";
}

sub DESTROY {
  my $self = shift;
  print "Foo($self->{x})->DESTROY()" . "\n";
}

package main;

my $a = new Foo(1);
my $x;

print "----- scope in  -----\n";
{
  my $b = new Foo(2);
  $b->func();
  $x = $b;
}
print "----- scope out -----\n";

$a->func();

Foo::new(1)

----- scope in  -----

Foo::new(2)

Foo(2)->func()

----- scope out -----

Foo(1)->func()

Foo(2)->DESTROY()

Foo(1)->DESTROY()