my $regexp = qr/Some Regex/;
warn "It's regexpable!" if $regexp->DOES( 'REGEX' );

my $subref = sub { ... };
warn "It's invokable!\n" if $subref->DOES( 'CODE' );

my $overloaded = Way::OverLoaded->new();
warn "It's indexable/keyable/invokable\n" if $overloaded->DOES( 'ARRAY' )
                                          && $overloaded->DOES( 'HASH' )
                                          && $overloaded->DOES( 'CODE' );