[ceph.git] / ceph / src / boost / libs / iterator / doc / zip_iterator_abstract.rst

.. Copyright David Abrahams 2006. Distributed under the Boost
.. Software License, Version 1.0. (See accompanying
.. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

The zip iterator provides the ability to parallel-iterate
over several controlled sequences simultaneously. A zip 
iterator is constructed from a tuple of iterators. Moving
the zip iterator moves all the iterators in parallel.
Dereferencing the zip iterator returns a tuple that contains
the results of dereferencing the individual iterators. 

The tuple of iterators is now implemented in terms of a Boost fusion sequence. 
Because of this the 'tuple' may be any Boost fusion sequence and, for backwards
compatibility through a Boost fusion sequence adapter, a Boost tuple. Because the 
'tuple' may be any boost::fusion sequence the 'tuple' may also be any type for which a 
Boost fusion adapter exists. This includes, among others, a std::tuple and a std::pair.
Just remember to include the appropriate Boost fusion adapter header files for these
other Boost fusion adapters. The zip_iterator header file already includes the
Boost fusion adapter header file for Boost tuple, so you need not include it yourself
to use a Boost tuple as your 'tuple'.
Commit	Line	Data
7c673cae FG	1	.. Copyright David Abrahams 2006. Distributed under the Boost
	2	.. Software License, Version 1.0. (See accompanying
	3	.. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
	4
	5	The zip iterator provides the ability to parallel-iterate
	6	over several controlled sequences simultaneously. A zip
	7	iterator is constructed from a tuple of iterators. Moving
	8	the zip iterator moves all the iterators in parallel.
	9	Dereferencing the zip iterator returns a tuple that contains
	10	the results of dereferencing the individual iterators.
	11
	12	The tuple of iterators is now implemented in terms of a Boost fusion sequence.
	13	Because of this the 'tuple' may be any Boost fusion sequence and, for backwards
	14	compatibility through a Boost fusion sequence adapter, a Boost tuple. Because the
	15	'tuple' may be any boost::fusion sequence the 'tuple' may also be any type for which a
	16	Boost fusion adapter exists. This includes, among others, a std::tuple and a std::pair.
	17	Just remember to include the appropriate Boost fusion adapter header files for these
	18	other Boost fusion adapters. The zip_iterator header file already includes the
	19	Boost fusion adapter header file for Boost tuple, so you need not include it yourself
	20	to use a Boost tuple as your 'tuple'.