The BOOST_PP_TUPLE_INSERT_D macro
      inserts an element into a tuple.  It reenters BOOST_PP_WHILE
      with maximum efficiency.
    Usage
     BOOST_PP_TUPLE_INSERT_D(
d, 
tuple,
      
i, 
elem) 
(v) 
    Arguments
    
      - d
-  The next available BOOST_PP_WHILE iteration. 
- tuple
-  The tuple into which an element is to be inserted.
- i
-  The zero-based position in tuple where an element is to be
        inserted.  Valid values range from 0 to BOOST_PP_TUPLE_SIZE(tuple).
- elem
-  The element to insert. 
Remarks
     This macro inserts elem before the element at index i.
    
     If the operation attempts to create an tuple that is larger
      than BOOST_PP_LIMIT_TUPLE, the result is undefined.
    See Also
    
    Requirements
    
    
     © Copyright Edward Diener 2013