Update todos

src/models.rs

@@ -1,4 +1,3 @@
-// TODO: Vertex (and Incidence?) should be references of Graph data, not plain indices into the internal (Vec) data structures.
 // TODO: Vertex value must not be public.
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub struct Vertex(pub usize);
@@ -14,7 +13,10 @@ pub struct VertexIncidenceHeader {
     pub first_incidence: Option<Incidence>,
 }
 
+// TODO: Graph cannot support deleting vertices because of the external indices "Vertex". They could be made stable with e.g. slotmap or generational arena.
 // TODO: Graph fields must not be public.
+// TODO: Add functions to reserve memory for vertices and edges.
+// TODO: Add function to delete edges.
 pub struct Graph {
     // TODO: Index 'incidence_headers' by a 'Vertex' instead of 'Vertex.0'?
     pub incidence_headers: Vec<VertexIncidenceHeader>,
@@ -62,7 +64,6 @@ impl Graph {
         }
     }
 
-    // TODO: 'fn add_vertex()' should not be publicly accessible for all graph implementations.
     // TODO: 'fn add_vertex()' needs variants for custom vertex data.
     pub fn add_vertex(&mut self) -> Vertex {
         self.incidence_headers.push(VertexIncidenceHeader {
@@ -72,7 +73,6 @@ impl Graph {
         Vertex(self.incidence_headers.len() - 1)
     }
 
-    // TODO: 'fn add_edge()' should not be publicly accessible for all graph implementations.
     // TODO: 'fn add_edge()' needs variants for custom edge data.
     pub fn add_edge(&mut self, v1: Vertex, v2: Vertex) {
         self.add_incidence(v1, v2);