Reducing functions
==================

As we say in the :ref:`design` section, a transducer in itself is agnostic of
any actual sequence.  To use a transducer, you pass it a *reducing function*, to
obtain a new reducing function that can then be used in a :ref:`process`.

output
------
.. doxygenvariable:: output

first
-----
.. doxygenvariable:: first

last
-----
.. doxygenvariable:: last

emplacing_back
--------------
.. doxygenvariable:: emplacing_back