From 81e9b5e14f95a03ea536b71a7c86034bd6389c4c Mon Sep 17 00:00:00 2001
From: Phil Ratzloff <pratzl@outlook.com>
Date: Thu, 7 Dec 2023 14:23:03 -0500
Subject: [PATCH] Updates to reflect P1709 changes

null_range --> null_predecessors in dijkstra_clrs
Add neighbor_descriptor for consistency
Tweak index_adjacency_list
---
 include/graph/algorithm/dijkstra_clrs.hpp |  2 +-
 include/graph/graph.hpp                   | 18 +++++++++++++-----
 include/graph/graph_descriptors.hpp       |  9 +++++++++
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/include/graph/algorithm/dijkstra_clrs.hpp b/include/graph/algorithm/dijkstra_clrs.hpp
index ccb94d3..e50039d 100644
--- a/include/graph/algorithm/dijkstra_clrs.hpp
+++ b/include/graph/algorithm/dijkstra_clrs.hpp
@@ -50,7 +50,7 @@ class null_range_type : public std::vector<size_t> {
   null_range_type(std::initializer_list<T> init, const Allocator& alloc = Allocator()) {}
 };
 
-inline static null_range_type null_range;
+inline static null_range_type null_predecessors;
 
 
 template <class... Ts>
diff --git a/include/graph/graph.hpp b/include/graph/graph.hpp
index 3393326..5e63849 100644
--- a/include/graph/graph.hpp
+++ b/include/graph/graph.hpp
@@ -104,13 +104,16 @@ inline constexpr bool is_undirected_edge_v = false;
  * @tparam G The graph type.
  */
 template <class G>
-concept vertex_range = ranges::forward_range<vertex_range_t<G>> && ranges::sized_range<vertex_range_t<G>> && //
-                       requires(G&& g, vertex_iterator_t<G> ui) { vertex_id(g, ui); };
+concept _common_vertex_range = ranges::sized_range<vertex_range_t<G>> && //
+                               requires(G&& g, vertex_iterator_t<G> ui) { vertex_id(g, ui); };
 
 template <class G>
-concept index_vertex_range = ranges::random_access_range<vertex_range_t<G>> && ranges::sized_range<vertex_range_t<G>> &&
-                             integral<vertex_id_t<G>> && //
-                             requires(G&& g, vertex_iterator_t<G> ui) { vertex_id(g, ui); };
+concept vertex_range = _common_vertex_range<G> && ranges::forward_range<vertex_range_t<G>>;
+
+template <class G>
+concept index_vertex_range = _common_vertex_range<G> && //
+                             ranges::random_access_range<vertex_range_t<G>> && integral<vertex_id_t<G>>;
+
 
 /**
  * @ingroup graph_concepts
@@ -202,6 +205,11 @@ concept index_adjacency_list = basic_index_adjacency_list<G> && requires(G&& g,
   { edges(g, u) } -> ranges::forward_range;
 };
 
+//template <class G>
+//concept index_adjacency_list = adjacency_list<G> && //
+//                               ranges::random_access_range<vertex_range_t<G>> && integral<vertex_id_t<G>>;
+
+
 // !is_same_v<vertex_range_t<G>, vertex_edge_range_t<G>>
 //      CSR fails this condition b/c row_index & col_index are both index_vectors; common?
 
diff --git a/include/graph/graph_descriptors.hpp b/include/graph/graph_descriptors.hpp
index 761d8cd..9c6cd20 100644
--- a/include/graph/graph_descriptors.hpp
+++ b/include/graph/graph_descriptors.hpp
@@ -268,6 +268,12 @@ struct neighbor_descriptor<VId, true, void, void> {
   target_id_type target_id;
 };
 
+//
+// copyable_edge_t
+//
+template <class VId, class VV>
+using copyable_neighbor_t = neighbor_descriptor<VId, true, void, VV>; // {source_id, target_id [, value]}
+
 //
 // view concepts
 //
@@ -277,6 +283,9 @@ concept copyable_vertex = convertible_to<T, copyable_vertex_t<VId, VV>>;
 template <class T, class VId, class EV>
 concept copyable_edge = convertible_to<T, copyable_edge_t<VId, EV>>;
 
+template <class T, class VId, class EV>
+concept copyable_neighbor = convertible_to<T, copyable_neighbor_t<VId, EV>>;
+
 //
 // is_sourced<G>
 //