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11.8.1. Problem

Create a closure that makes the proper method call on the appropriate
object.

When you ask for a reference to a method, you're asking for more than
just a raw function pointer. You also need to record which object the
method needs to be called upon as the object contains the data the
method will work with. The best way to do this is using a closure.
Assuming $obj is lexically scoped, you can say:

$mref = sub { $obj->meth(@_) };
# later...
$mref->("args", "go", "here");

Even when $obj goes out of scope, the closure
stored in $mref has captured it. Later when it's
called indirectly, the correct object is used for the method call.

Be aware that the notation:

$sref = \$obj->meth;

doesn't do what you probably expected. It first calls the method on
that object and gives you either a reference to the return value or a
reference to the last of the return values if the method returns a
list.

The can method from the UNIVERSAL base class,
while appealing, is also unlikely to produce what you want.

$cref = $obj->can("meth");

This produces a code ref to the appropriate method (should one be
found), but one that carries no object information. Think of it as a
raw function pointer. The information about the object is lost.
That's why you need a closure to capture both the object state as
well as the method to call.