resolved comments

Author: SpectraL519

include/gl/impl/adjacency_matrix.hpp

@@ -138,9 +138,7 @@ class adjacency_matrix final {
     }
 
     [[nodiscard]] bool has_edge(const edge_type& edge) const {
-        const auto first_id = edge.first();
-        const auto second_id = edge.second();
-
+        const auto [first_id, second_id] = edge.incident_vertices();
         if (not (this->_is_valid_vertex_id(first_id) and this->_is_valid_vertex_id(second_id)))
             return false;
 

include/gl/impl/specialized/adjacency_matrix.hpp

@@ -265,13 +265,10 @@ struct undirected_adjacency_matrix {
             detail::strict_get<impl_type>(self._matrix, &edge) = nullptr;
         }
         else {
-            const auto first_id = edge.first();
-            const auto second_id = edge.second();
-
             detail::strict_get<impl_type>(self._matrix, &edge) = nullptr;
             // if the edge was found in the first matrix cell,
             // it will also be present in the second matrix cell
-            self._matrix[second_id][first_id] = nullptr;
+            self._matrix[edge.second()][edge.first()] = nullptr;
         }
         --self._n_unique_edges;
     }