Tuples

A tuple is a simple comma-separated list of elements inside parenthesis.  For example,
(a, b, c)
...is a tuple of 3 elements--a, b, and c.
Tuples are fast and easy to use.  However, all access to tuples requires knowledge of its size.
Elements of a tuple can be extracted with BOOST_PP_TUPLE_ELEM.

Primitives