remove dead code

src/cargo/core/resolver/context.rs

@@ -13,7 +13,7 @@ use crate::util::CargoResult;
 use crate::util::Graph;
 
 use super::errors::ActivateResult;
-use super::types::{ConflictMap, ConflictReason, DepInfo, GraphNode, Method, RegistryQueryer};
+use super::types::{ConflictMap, ConflictReason, DepInfo, Method, RegistryQueryer};
 
 pub use super::encode::{EncodableDependency, EncodablePackageId, EncodableResolve};
 pub use super::encode::{Metadata, WorkspaceResolve};

src/cargo/core/resolver/mod.rs

@@ -62,7 +62,7 @@ use crate::util::errors::CargoResult;
 use crate::util::profile;
 
 use self::context::{Activations, Context};
-use self::types::{Candidate, ConflictMap, ConflictReason, DepsFrame, GraphNode};
+use self::types::{Candidate, ConflictMap, ConflictReason, DepsFrame};
 use self::types::{RcVecIter, RegistryQueryer, RemainingDeps, ResolverProgress};
 
 pub use self::encode::{EncodableDependency, EncodablePackageId, EncodableResolve};

src/cargo/core/resolver/types.rs

@@ -491,50 +491,3 @@ where
 }
 
 impl<T: Clone> ExactSizeIterator for RcVecIter<T> {}
-
-pub struct RcList<T> {
-    pub head: Option<Rc<(T, RcList<T>)>>,
-}
-
-impl<T> RcList<T> {
-    pub fn new() -> RcList<T> {
-        RcList { head: None }
-    }
-
-    pub fn push(&mut self, data: T) {
-        let node = Rc::new((
-            data,
-            RcList {
-                head: self.head.take(),
-            },
-        ));
-        self.head = Some(node);
-    }
-}
-
-// Not derived to avoid `T: Clone`
-impl<T> Clone for RcList<T> {
-    fn clone(&self) -> RcList<T> {
-        RcList {
-            head: self.head.clone(),
-        }
-    }
-}
-
-// Avoid stack overflows on drop by turning recursion into a loop
-impl<T> Drop for RcList<T> {
-    fn drop(&mut self) {
-        let mut cur = self.head.take();
-        while let Some(head) = cur {
-            match Rc::try_unwrap(head) {
-                Ok((_data, mut next)) => cur = next.head.take(),
-                Err(_) => break,
-            }
-        }
-    }
-}
-
-pub enum GraphNode {
-    Add(PackageId),
-    Link(PackageId, PackageId, Dependency),
-}