ap
     > **{};**


Default Arguments Unsupported on Nested Templates
=================================================

As of this writing, Borland compilers don't support the use of
default template arguments on member class templates.  As a result,
you have to supply ``BOOST_PARAMETER_MAX_ARITY`` arguments to every
use of ``parameters<…>::match``.  Since the actual defaults used
are unspecified, the workaround is to use
|BOOST_PARAMETER_MATCH|_ to declare default arguments for SFINAE.

.. |BOOST_PARAME