Make infcx on OpportunisticRegionResolver mut

Author: jyn514

compiler/rustc_infer/src/infer/nll_relate/mod.rs

@@ -877,7 +877,7 @@ where
             }
 
             ty::Infer(ty::TyVar(vid)) => {
-                let variables = self.delegate.infcx().inner.type_variables();
+                let mut variables = self.delegate.infcx().inner.type_variables();
                 let vid = variables.root_var(vid);
                 let sub_vid = variables.sub_root_var(vid);
                 if sub_vid == self.for_vid_sub_root {

compiler/rustc_infer/src/infer/outlives/env.rs

@@ -158,7 +158,7 @@ impl<'a, 'tcx> OutlivesEnvironment<'tcx> {
     /// `RegionConstraintData`.)
     pub fn add_outlives_bounds<I>(
         &mut self,
-        infcx: Option<&InferCtxt<'a, 'tcx>>,
+        infcx: Option<&mut InferCtxt<'a, 'tcx>>,
         outlives_bounds: I,
     ) where
         I: IntoIterator<Item = OutlivesBound<'tcx>>,
@@ -172,7 +172,7 @@ impl<'a, 'tcx> OutlivesEnvironment<'tcx> {
                     r_a @ (&ty::ReEarlyBound(_) | &ty::ReFree(_)),
                     &ty::ReVar(vid_b),
                 ) => {
-                    infcx.expect("no infcx provided but region vars found").add_given(r_a, vid_b);
+                    infcx.as_mut().expect("no infcx provided but region vars found").add_given(r_a, vid_b);
                 }
                 OutlivesBound::RegionSubParam(r_a, param_b) => {
                     self.region_bound_pairs_accum.push((r_a, GenericKind::Param(param_b)));

compiler/rustc_infer/src/infer/resolve.rs

@@ -55,17 +55,17 @@ impl<'a, 'tcx> TypeFolder<'tcx> for OpportunisticVarResolver<'a, '_, 'tcx> {
 ///
 /// If you want to resolve type and const variables as well, call
 /// [InferCtxt::resolve_vars_if_possible] first.
-pub struct OpportunisticRegionResolver<'a, 'tcx> {
-    infcx: &'a InferCtxt<'a, 'tcx>,
+pub struct OpportunisticRegionResolver<'a, 'cx, 'tcx> {
+    infcx: &'a mut InferCtxt<'cx, 'tcx>,
 }
 
-impl<'a, 'tcx> OpportunisticRegionResolver<'a, 'tcx> {
-    pub fn new(infcx: &'a InferCtxt<'a, 'tcx>) -> Self {
+impl<'a, 'cx, 'tcx> OpportunisticRegionResolver<'a, 'cx, 'tcx> {
+    pub fn new(infcx: &'a mut InferCtxt<'cx, 'tcx>) -> Self {
         OpportunisticRegionResolver { infcx }
     }
 }
 
-impl<'a, 'tcx> TypeFolder<'tcx> for OpportunisticRegionResolver<'a, 'tcx> {
+impl<'a, 'tcx> TypeFolder<'tcx> for OpportunisticRegionResolver<'a, '_, 'tcx> {
     fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }