complete BOOST_PP_SEQ_TO_TUPLE

[Wolf Lammen <ookami1@…>]

Feature completion, symmetric behavior:

While BOOST_PP_TUPLE_TO_SEQ turns an empty tuple () into an empty sequence (i.e. nothing), the reverse operation BOOST_PP_SEQ_TO_TUPLE cannot turn an empty sequence to (). The attached patch fixes this, and, as a side effect, extends BOOST_PP_SEQ_ENUM to accept empty sequences as well.

Cheers,

Wolf Lammen

[Edward Diener]

There is no such thing as an empty tuple or an empty seq. A tuple of '()' is a one element tuple whose data is empty. A seq of '()' is a seq of a single element whose data is empty. Converting between a seq and a tuple now works each way to produce the correct result.