=over

=item bless REF,CLASSNAME
X<bless>

=item bless REF

C<bless> tells Perl to mark the item referred to by C<REF> as an
object in a package.  The two-argument version of C<bless> is
always preferable unless there is a specific reason to I<not>
use it.

=over

=item * Bless the referred-to item into a specific package
(recommended form):

    bless $ref, $package;

The two-argument form adds the object to the package specified
as the second argument.

=item * Bless the referred-to item into package C<main>:

    bless $ref, "";

If the second argument is an empty string, C<bless> adds the
object to package C<main>.

=item * Bless the referred-to item into the current package (not
inheritable):

    bless $ref;

If C<bless> is used without its second argument, the object is
created in the current package. The second argument should
always be supplied if a derived class might inherit a method
executing C<bless>. Because it is a potential source of bugs,
one-argument C<bless> is discouraged.

=back

See L<perlobj> for more about the blessing (and blessings) of
objects.

L<C<bless>|/bless REF,CLASSNAME> returns its first argument, the
supplied reference, as the value of the function; since C<bless>
is commonly the last thing executed in constructors, this means
that the reference to the object is returned as the
constructor's value and allows the caller to immediately use
this returned object in method calls.

C<CLASSNAME> should always be a mixed-case name, as
all-uppercase and all-lowercase names are meant to be used only
for Perl builtin types and pragmas, respectively. Avoid creating
all-uppercase or all-lowercase package names to prevent
confusion.

Also avoid C<bless>ing things into the class name C<0>; this
will cause code which (erroneously) checks the result of
L<C<ref>|/ref EXPR> to see if a reference is C<bless>ed to fail,
as "0", a false value, is returned.

See L<perlmod/"Perl Modules"> for more details.

=back