php - smarty accessing variables with double colon -

smarty's {debug} output has value pub-id::doi need access:

{foo} publishedarticle object    ->_data = array   ...       pub-id::doi => "10.5334/aa.12302"   ...  

but have no idea how because key contains double colon.

per documentation

if doi constant can assign smarty variable doing following

{assign var=foo value=pub-id::doi} 

if doi member variable of class

{assign var=foo value=pub-id::$doi}