Particle Pair Loop
==================

This section contains documentation for particle pair looping.
Particle pair looping is a looping type similar to particle loop except that
the kernel operates on two particles.

.. list-table::  Constructs that are passable to Particle Pair Loops
   :header-rows: 1

   * - Construct
     - Access Modes
   * - CellDatConst
     - Read, Write, Add, Min, Max
   * - DescendantProducts
     - Write
   * - LocalArray
     - Read, Write, Add
   * - MaskArray
     - Read, Write
   * - NDLocalArray
     - Read, Write, Add, Max, Min
   * - ParticleMask
     - Read, Write
   * - SymVector
     - Read, Write
   * - ParticlePairLoopIndex
     - Read
   * - KernelRNG
     - Read
   * - TupleRNG
     - Read



.. doxygengroup:: particle_pair_loop
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Pair Lists Absolute
-------------------

These types define iteration sets for Particle Pair Loops. The type of the iteration set determines which pair loop is executed. Typically these absolute pair lists are constructed from pair lists that inherit a base class that corresponds to the pair list type.


.. doxygengroup:: particle_pair_loop_cellwise_pair_list_absolute
  :content-only:
  :members:

Host Pair List
--------------

The host pair list is a simple pair list construct where pairs are specified only on the host.


.. doxygengroup:: particle_pair_loop_host_pair_list
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  :members:

Simple Pair List
----------------

This simple pair list is a pair list construct where pairs are specified on the host.


.. doxygengroup:: particle_pair_loop_simple_pair_list
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Particle Pair Loop Functions
----------------------------

Functions that create Particle Pair Loops. These functions accept an absolute pair list as the iteration set specification.


.. doxygengroup:: particle_pair_loop_functions
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  :members:

PairMask
--------

Construct for masking off pairs of particles, i.e. storing a boolean per particle pair.


.. doxygengroup:: particle_pair_loop_pair_mask
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  :members:

Helper Functions
----------------

Helper functions for working with pair looping.


.. doxygengroup:: particle_pair_loop_helper_functions
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Base Type
---------

Base type from which all Particle Pair Loops inherit.


.. doxygengroup:: particle_pair_loop_base_type
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ParticlePairLoopIndex
---------------------

Particle Pair Loop construct for identifying the indices of particles in pairs.


.. doxygengroup:: particle_pair_loop_particle_pair_loop_index
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