1 files changed, 15 insertions, 1 deletions
diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index b7f5ed9d004..e198b008753 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -1,10 +1,24 @@
 use rustc::hir;
 use rustc::traits::auto_trait::{self, AutoTraitResult};
-use rustc::ty::{self, TypeFoldable};
+use rustc::ty::{self, Region, RegionVid, TypeFoldable};
+use rustc::util::nodemap::FxHashSet;
+
 use std::fmt::Debug;
 
 use super::*;
 
+#[derive(Eq, PartialEq, Hash, Copy, Clone, Debug)]
+enum RegionTarget<'tcx> {
+    Region(Region<'tcx>),
+    RegionVid(RegionVid)
+}
+
+#[derive(Default, Debug, Clone)]
+struct RegionDeps<'tcx> {
+    larger: FxHashSet<RegionTarget<'tcx>>,
+    smaller: FxHashSet<RegionTarget<'tcx>>
+}
+
 pub struct AutoTraitFinder<'a, 'tcx> {
     pub cx: &'a core::DocContext<'tcx>,
     pub f: auto_trait::AutoTraitFinder<'tcx>,