The BOOST_PP_TUPLE_POP_BACK_Z macro
      pops an element from the end of an tuple.  It reenters BOOST_PP_REPEAT
      with maximum efficiency. 
    Usage
     BOOST_PP_TUPLE_POP_BACK_Z(
z, 
tuple)
      
(v) 
    Arguments
    
      - z
-  The next available BOOST_PP_REPEAT dimension. 
- tuple
-  The tuple to pop an element from.
Remarks
     This macro returns tuple after removing the last
      element.  If tuple has only a single element, it remains
      unchanged since a tuple must have at least one element.
    See Also
    
    Requirements
    
    
     © Copyright Edward Diener 2013