Adjacency
=========

:cpp:include:`#include<hysj/graphs/adjacency.hpp>`

.. cpp:namespace:: hysj::graphs

In namespace :cpp:any:`graphs`:

.. cpp:function:: template<element_tag T> auto semiadjacent(constant_t<T> t,auto d0,auto d1,const auto &g,auto i)

   | Hook to compute the semiadjacent ids of :cpp:var:`i`. These are computed by first computing the incident ids in direction :cpp:var:`d0`, and from each of those, computing the incident ids in the direction :cpp:var:`d1`.
   |

.. cpp:function:: auto exclusive_semiadjacent(auto t,auto d0,auto d1,const auto &g,auto i)

   | The semiadjacent of :cpp:var:`i`, modulo :cpp:var:`i` itself.
   |

.. cpp:function:: template<element_tag T> auto adjacent(constant_t<T> t,auto d,const auto &g,auto i)const

   | Hook for computing the adjacent elements of :cpp:var:`i`. The default behaviour computes them via :cpp:expr:`semiadjacent(t,d,d,g,i)`. 

*Traits*

.. cpp:type:: template<element_tag T,typename D,typename G,typename I> traits::adjacent_t

   | The deduced retur-type of :cpp:expr:`adjacent` invoked with these types parameters.

*Concepts*

.. cpp:concept:: template<typename G,element_tag T,typename D,typename I> concepts::adjacency_graph

   | A graph that supports the adjacency relation for elements of type :cpp:expr:`T`, identified by :cpp:expr:`I`, in the direction-specifier of :cpp:type:`D`.

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