Apply Copilot recommended changes to the following files:

graph.hpp
graph_cpo.hpp
graph_using.hpp

One bug was fixed in has_edge function in graph_cpo.hpp:

Author: pratzl

include/graph/detail/graph_cpo.hpp

@@ -97,7 +97,7 @@ concept _el_index_tuple_edge = _el_tuple_edge<_E> && //
                                integral<tuple_element_t<0, _E>>;
 
 //
-// Suport the use of edge_info for edgelist edge definitions
+// Support the use of edge_info for edgelist edge definitions
 // (Only types and values needed from edge_info are used and there is no
 // explicit use of edge_info. This is deemed more flexible and no
 // functionality is compromised for it.)
@@ -1319,9 +1319,9 @@ namespace _Source {
      * Complexity: O(1)
      * 
      * Default implementation: *(begin(vertices(g)) + source_id(g, uv)), 
-     #         if @source_id(g,uv) is defined for G and random_access_range<vertex_range_t<G>>
+     *         if @source_id(g,uv) is defined for G and random_access_range<vertex_range_t<G>>
      * 
-     * Not all graphs support a source on an edge. The existance of @c source_id(g,uv) function 
+     * Not all graphs support a source on an edge. The existence of @c source_id(g,uv) function 
      * for a graph type G determines if it is considered a "sourced" edge or not. If it is, 
      * @c source(g,uv) will also exist.
      * 
@@ -2561,7 +2561,7 @@ namespace _HasEdge {
         return has_edge(__g); // intentional ADL
       } else if constexpr (_Strat_id == _St_ref::_Auto_eval) {
         for (auto&& u : vertices(__g))
-          if (empty(edges(__g, u)))
+          if (!empty(edges(__g, u)))
             return true;
         return false;
       } else {

include/graph/detail/graph_using.hpp

@@ -5,6 +5,10 @@
 #include <tuple>
 #include <functional>
 #include <optional>
+#include <type_traits>
+#include <iterator>
+#include <algorithm>
+#include <memory>
 
 namespace graph {
 // Containers are not included to avoid potential conflicts: vector, list, string, etc.
@@ -19,6 +23,8 @@ using std::forward_iterator_tag;
 using std::declval;
 using std::allocator;
 using std::allocator_traits;
+using std::unique_ptr;
+using std::shared_ptr;
 
 using std::iter_difference_t;
 using std::iter_value_t;
@@ -40,7 +46,6 @@ using std::is_arithmetic_v;
 using std::is_convertible_v;
 using std::is_same_v;
 using std::is_invocable_v;
-using std::is_arithmetic_v;
 using std::is_void_v;
 using std::is_lvalue_reference_v;
 using std::is_signed_v;
@@ -52,6 +57,7 @@ using std::remove_reference_t;
 using std::remove_pointer_t;
 using std::remove_cvref_t;
 using std::invoke_result_t;
+using std::decay_t;
 
 using std::false_type;
 using std::true_type;
@@ -62,6 +68,7 @@ using std::convertible_to;
 using std::integral;
 using std::invocable;
 using std::regular_invocable;
+using std::predicate;
 
 // range concepts
 using std::ranges::range;
@@ -110,4 +117,6 @@ using std::ranges::empty;
 using std::tuple_cat;
 using std::max;
 using std::min;
+using std::swap;
+using std::is_sorted;
 } // namespace graph

include/graph/graph.hpp

@@ -7,7 +7,12 @@
  * @defgroup graph_views        Views / Adaptors
  * @defgroup graph_containers   Containers
  * @defgroup graph_construction Graph Construction
- * @defgroup graph_io           Graph I/O
+ * @defgroup graph_io  #  ifdef ENABLE_EDGELIST_RANGE
+template <class ELR>
+concept basic_edgelist_range = std::ranges::forward_range<ELR> && std::negation_v<basic_adjacency_list<ELR>>;
+template <class ELR>
+concept edgelist_range = std::ranges::forward_range<ELR> && std::negation_v<adjacency_list<ELR>>;
+#  endif   Graph I/O
  * @defgroup graph_utilities    Utilities
  * 
  * @defgroup graph_concepts Graph Concepts
@@ -283,7 +288,7 @@ concept edgelist_range = ranges::forward_range<ELR> && negation_v<adjacency_list
 
 /**
  * @ingroup graph_properties
- * @brief Concept for the existance of degree function for graph G.
+ * @brief Concept for the existence of degree function for graph G.
  * 
  * Returns true if degree(g) exists for graph G.
  * 
@@ -300,7 +305,7 @@ concept has_degree = requires(G&& g, vertex_reference_t<G> u) {
 
 /**
  * @ingroup graph_properties
- * @brief Concept for the existance of the find_vertex(g,uid) function for graph G.
+ * @brief Concept for the existence of the find_vertex(g,uid) function for graph G.
  * 
  * Returns true if find_vertex(g,uid) exists for graph G.
  * 
@@ -313,7 +318,7 @@ concept has_find_vertex = requires(G&& g, vertex_id_t<G> uid) {
 
 /**
  * @ingroup graph_properties
- * @brief Concept for the existance of the find_vertex_edge(g,uid,vid) function for graph G.
+ * @brief Concept for the existence of the find_vertex_edge(g,uid,vid) function for graph G.
  * 
  * Returns true if find_vertex_edge(g,u,vid) and find_vertex_edge(g,uid,vid) exists for graph G.
  * 
@@ -327,7 +332,7 @@ concept has_find_vertex_edge = requires(G&& g, vertex_id_t<G> uid, vertex_id_t<G
 
 /**
  * @ingroup graph_properties
- * @brief Concept for the existance of the has_contains_edge(g,uid,vid) function for graph G.
+ * @brief Concept for the existence of the has_contains_edge(g,uid,vid) function for graph G.
  * 
  * Returns true if has_contains_edge(g,uid,vid) exists for graph G.
  * 
@@ -341,7 +346,7 @@ concept has_contains_edge = requires(G&& g, vertex_id_t<G> uid, vertex_id_t<G> v
 
 /**
  * @ingroup graph_properties
- * @ brief Specializable to define that a graph type has unordered edges.
+ * @brief Specializable to define that a graph type has unordered edges.
  * 
  * Override for a graph type where source_id and target_id are unordered
  * on an edge so views and algorithms know to choose the correct target
@@ -362,7 +367,7 @@ concept has_contains_edge = requires(G&& g, vertex_id_t<G> uid, vertex_id_t<G> v
  *  namespace my_namespace {
  *      template <class T>
  *      class my_graph { ... };
- *      template class< T>
+ *      template <class T>
  *      class my_edge { int src_id; int tgt_id; ... };
  *  }
  *  namespace graph {