Exception Objects 

• But $@ might be just a string

if(ref($@)  and  $@->isa('Exception::ICanHandle')) {
  # Do stuff
}

• Or not an object

use Scalar::Util qw(blessed);

if(blessed($@)  and  $@->isa('Exception::ICanHandle')) {
  # Do stuff
}

• A pragmatic solution

if(UNIVERSAL::isa($@, 'Exception::ICanHandle')) {
  # Do stuff
}