$ perl -MO=Deparse -e 'tied sub {}->()'
tied {sub {
    
}
}->();
-e syntax OK

##</code><code>##

$ perl -e 'tied { sub {} }->()'
Not a subroutine reference at -e line 1.

##</code><code>##

$ perl -e 'tied { sub {}->() }'
Can't modify anonymous hash ({}) in tied at -e line 1, at EOF
Execution of -e aborted due to compilation errors.