Manual:DIL Manual/secure()

secure ( u : unitptr , label )
   u : Unit to secure.
   label : Label to jump to, on removal.
   result: Secures a unitptr, so that the program will go to 'label'
           if unit leaves local environment. If this happens, during
           a call to another function/procedure, it will continue
           at that label when the function/procedure returns.
           If you perform some kind of call to a template, the removing
           of a unit from the local environment will not have affect.
           until the return from that function, as the program execution
           will continue at the designated label after a call. Should
           several secured units leave local environment, the last such
           event will determine the point of execution upon return.