Incidence
=========

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

.. cpp:namespace:: hysj

.. cpp:namespace-push:: graphs

In namespace :cpp:any:`graphs`:

.. cpp:enum:: incidence_tag

   .. rest-script::

      from hysj.graphs import IncidenceTag as Enum

      for e in Enum.__members__.values():
        print(f'.. cpp:enumerator:: {e.name}')

   | Names the types of incidence a graph can support.
   |

.. cpp:function:: auto incident(auto tag,auto direction,const auto &graph,auto id)

   | Hook for accessing the incident elements of :cpp:expr:`id`.

*Shorthands*

.. rest-script::

   from hysj.graphs import *
   for e in ElementTag.__members__.values():
     print(f'.. cpp:var:: unspecified {e.name[0]}incident = bind(incident,{e.name}_tag)')

*Traits*

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

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

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

   | Short hand for the value-type of :cpp:type:`traits::incident_t`.
   |

*Concepts*

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

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

|

.. cpp:function:: auto port(auto direction,const auto &graph,auto id)

   | Function computing the incident vertex of :cpp:var:`id` in :cpp:var:`direction`.
   | 

*Shorthands*

.. cpp:var:: unspecified head = bind(port,in_tag)
	     unspecified tail = bind(port,out_tag)

   |
   
.. cpp:function:: template<typename G,typename I> auto ports(const G &g,I i)

   | Returns a tuple of the incident vertices of the edge :cpp:var:`i`.
   |

Builtin
-------

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

.. cpp:namespace-push:: builtin
		
In namespace :cpp:any:`builtin`:

.. cpp:struct:: template<incidence_tag G,typename V,typename E> incidence_graph

   | Implements :cpp:concept:`concepts::incidence_graph`, :cpp:concept:`concepts::element_property_of`, for :cpp:expr:`element_tag::vertex` and :cpp:type:`V`, and :cpp:expr:`element_tag::edge` and :cpp:type:`E`.
   |
	
.. cpp:namespace-pop::

.. cpp:namespace-pop::