YT-CPPHGL-9: Introduce storage layout tags to define the layout of incidence list and matrix representation models

- Defined new `vertex_major_t` and `hyperedge_major_t` implementation layout tags with utility methods for retrieving the major and minor elements
- Replaced the current implementation tags with template `list_t` and `matrix_t` tags parametrized with a storage layout tag
- Merged the `undirected_hyperedge_list` and `undirected_vertex_list` classes into a single template class `undirected_incidence_list<LayoutTag>`
- Add a `LayoutTag` template parameter to the `unidrected_incidence_matrix` class and aligned its implementation to use layout-dependent behaviour
- Aligned the `hypergraph_traits` type and related utility to use the new tags

Author: SpectraL519

include/hgl/hypergraph_traits.hpp

@@ -7,14 +7,15 @@
 #include "directional_tags.hpp"
 #include "hypergraph_elements.hpp"
 #include "impl/impl_tags.hpp"
+#include "impl/layout_tags.hpp"
 
 namespace hgl {
 
 template <
     type_traits::c_hypergraph_directional_tag DirectionalTag = undirected_t,
     type_traits::c_properties VertexProperties = types::empty_properties,
     type_traits::c_properties HyperedgeProperties = types::empty_properties,
-    type_traits::c_hypergraph_impl_tag ImplTag = impl::hyperedge_list_t>
+    type_traits::c_hypergraph_impl_tag ImplTag = impl::list_t<impl::hyperedge_major_t>>
 struct hypergraph_traits {
     using directional_tag = DirectionalTag;
     using implementation_tag = ImplTag;
@@ -27,64 +28,57 @@ struct hypergraph_traits {
 };
 
 template <
+    type_traits::c_hypergraph_layout_tag LayoutTag = impl::hyperedge_major_t,
     type_traits::c_hypergraph_directional_tag DirectionalTag = undirected_t,
     type_traits::c_properties VertexProperties = types::empty_properties,
     type_traits::c_properties HyperedgeProperties = types::empty_properties>
-using hyperedge_list_hg_traits =
-    hypergraph_traits<DirectionalTag, VertexProperties, HyperedgeProperties, impl::hyperedge_list_t>;
+using list_hypergraph_traits =
+    hypergraph_traits<DirectionalTag, VertexProperties, HyperedgeProperties, impl::list_t<LayoutTag>>;
 
 template <
+    type_traits::c_hypergraph_layout_tag LayoutTag = impl::hyperedge_major_t,
     type_traits::c_hypergraph_directional_tag DirectionalTag = undirected_t,
     type_traits::c_properties VertexProperties = types::empty_properties,
     type_traits::c_properties HyperedgeProperties = types::empty_properties>
-using vertex_list_hg_traits =
-    hypergraph_traits<DirectionalTag, VertexProperties, HyperedgeProperties, impl::vertex_list_t>;
-
-template <
-    type_traits::c_hypergraph_directional_tag DirectionalTag = undirected_t,
-    type_traits::c_properties VertexProperties = types::empty_properties,
-    type_traits::c_properties HyperedgeProperties = types::empty_properties>
-using incidence_matrix_hg_traits =
-    hypergraph_traits<DirectionalTag, VertexProperties, HyperedgeProperties, impl::incidence_matrix_t>;
+using matrix_hypergraph_traits = hypergraph_traits<
+    DirectionalTag,
+    VertexProperties,
+    HyperedgeProperties,
+    impl::matrix_t<LayoutTag>>;
 
 template <
     type_traits::c_properties VertexProperties = types::empty_properties,
     type_traits::c_properties HyperedgeProperties = types::empty_properties,
-    type_traits::c_hypergraph_impl_tag ImplTag = impl::hyperedge_list_t>
-using undirected_hg_traits =
+    type_traits::c_hypergraph_impl_tag ImplTag = impl::list_t<impl::hyperedge_major_t>>
+using undirected_hypergraph_traits =
     hypergraph_traits<undirected_t, VertexProperties, HyperedgeProperties, ImplTag>;
 
 template <
     type_traits::c_properties VertexProperties = types::empty_properties,
     type_traits::c_properties HyperedgeProperties = types::empty_properties,
-    type_traits::c_hypergraph_impl_tag ImplTag = impl::hyperedge_list_t>
-using bf_directed_hg_traits =
+    type_traits::c_hypergraph_impl_tag ImplTag = impl::list_t<impl::hyperedge_major_t>>
+using bf_directed_hypergraph_traits =
     hypergraph_traits<bf_directed_t, VertexProperties, HyperedgeProperties, ImplTag>;
 
 namespace type_traits {
 
 template <typename TraitsType>
-concept c_hyperedge_list_hg_traits =
-    c_instantiation_of<TraitsType, hypergraph_traits>
-    and std::same_as<typename TraitsType::implementation_tag, impl::hyperedge_list_t>;
-
-template <typename TraitsType>
-concept c_vertex_list_hg_traits =
+concept c_list_hypergraph_traits =
     c_instantiation_of<TraitsType, hypergraph_traits>
-    and std::same_as<typename TraitsType::implementation_tag, impl::vertex_list_t>;
+    and c_hypergraph_list_impl<typename TraitsType::implementation_tag>;
 
 template <typename TraitsType>
-concept c_incidence_matrix_hg_traits =
+concept c_matrix_hypergraph_traits =
     c_instantiation_of<TraitsType, hypergraph_traits>
-    and std::same_as<typename TraitsType::implementation_tag, impl::incidence_matrix_t>;
+    and c_hypergraph_matrix_impl<typename TraitsType::implementation_tag>;
 
 template <typename TraitsType>
-concept c_undirected_hg_traits =
+concept c_undirected_hypergraph_traits =
     c_instantiation_of<TraitsType, hypergraph_traits>
     and std::same_as<typename TraitsType::hyperedge_directional_tag, undirected_t>;
 
 template <typename TraitsType>
-concept c_bf_directed_hg_traits =
+concept c_bf_directed_hypergraph_traits =
     c_instantiation_of<TraitsType, hypergraph_traits>
     and std::same_as<typename TraitsType::hyperedge_directional_tag, bf_directed_t>;
 

include/hgl/impl/hyperedge_list.hpp

@@ -5,24 +5,35 @@
 #pragma once
 
 #include "hgl/types/type_traits.hpp"
+#include "hgl/types/types.hpp"
+#include "layout_tags.hpp"
 
 namespace hgl {
 
 namespace impl {
 
-struct hyperedge_list_t {};
+template <type_traits::c_hypergraph_layout_tag LayoutTag>
+struct list_t {
+    using layout_tag = LayoutTag;
+};
 
-struct vertex_list_t {};
-
-struct incidence_matrix_t {};
+template <type_traits::c_hypergraph_layout_tag LayoutTag>
+struct matrix_t {
+    using layout_tag = LayoutTag;
+};
 
 } // namespace impl
 
 namespace type_traits {
 
 template <typename T>
-concept c_hypergraph_impl_tag =
-    c_one_of<T, impl::hyperedge_list_t, impl::vertex_list_t, impl::incidence_matrix_t>;
+concept c_hypergraph_list_impl = c_instantiation_of<T, impl::list_t>;
+
+template <typename T>
+concept c_hypergraph_matrix_impl = c_instantiation_of<T, impl::matrix_t>;
+
+template <typename T>
+concept c_hypergraph_impl_tag = c_hypergraph_list_impl<T> or c_hypergraph_matrix_impl<T>;
 
 } // namespace type_traits