do not give ownership of the InferCtxt away

Author: nikomatsakis

src/librustc/infer/mod.rs

@@ -430,15 +430,15 @@ impl<'a, 'gcx, 'tcx> InferCtxtBuilder<'a, 'gcx, 'tcx> {
     }
 
     pub fn enter<F, R>(&'tcx mut self, f: F) -> R
-        where F: for<'b> FnOnce(InferCtxt<'b, 'gcx, 'tcx>) -> R
+        where F: for<'b> FnOnce(&InferCtxt<'b, 'gcx, 'tcx>) -> R
     {
         let InferCtxtBuilder {
             global_tcx,
             ref arena,
             ref fresh_tables,
         } = *self;
         let in_progress_tables = fresh_tables.as_ref();
-        global_tcx.enter_local(arena, |tcx| f(InferCtxt {
+        global_tcx.enter_local(arena, |tcx| f(&InferCtxt {
             tcx,
             in_progress_tables,
             projection_cache: RefCell::new(traits::ProjectionCache::new()),

src/librustc_typeck/check/mod.rs

@@ -189,7 +189,7 @@ impl<'a, 'tcx> MaybeInProgressTables<'a, 'tcx> {
 /// `bar()` will each have their own `FnCtxt`, but they will
 /// share the inherited fields.
 pub struct Inherited<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
-    infcx: InferCtxt<'a, 'gcx, 'tcx>,
+    infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
 
     tables: MaybeInProgressTables<'a, 'tcx>,
 
@@ -620,7 +620,7 @@ impl<'a, 'gcx, 'tcx> InheritedBuilder<'a, 'gcx, 'tcx> {
 }
 
 impl<'a, 'gcx, 'tcx> Inherited<'a, 'gcx, 'tcx> {
-    fn new(infcx: InferCtxt<'a, 'gcx, 'tcx>, def_id: DefId) -> Self {
+    fn new(infcx: &'a InferCtxt<'a, 'gcx, 'tcx>, def_id: DefId) -> Self {
         let tcx = infcx.tcx;
         let item_id = tcx.hir.as_local_node_id(def_id);
         let body_id = item_id.and_then(|id| tcx.hir.maybe_body_owned_by(id));