Auto merge of #35856 - phimuemue:master, r=brson

[rust.git] / src / librustc / ty / relate.rs

diff --git a/src/librustc/ty/relate.rs b/src/librustc/ty/relate.rs
index 8975a799be14328bd2ab057dbf7eafe5cf90e4e2..5c157ff32e7bbb846bd256f6b98c9c3315a07b61 100644 (file)
--- a/src/librustc/ty/relate.rs
+++ b/src/librustc/ty/relate.rs
@@ -14,7 +14,7 @@
 //! type equality, etc.
 
 use hir::def_id::DefId;
-use ty::subst::Substs;
+use ty::subst::{Kind, Substs};
 use ty::{self, Ty, TyCtxt, TypeFoldable};
 use ty::error::{ExpectedFound, TypeError};
 use std::rc::Rc;
@@ -71,8 +71,8 @@ fn relate_with_variance<T: Relate<'tcx>>(&mut self,
     fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>)
            -> RelateResult<'tcx, Ty<'tcx>>;
 
-    fn regions(&mut self, a: ty::Region, b: ty::Region)
-               -> RelateResult<'tcx, ty::Region>;
+    fn regions(&mut self, a: &'tcx ty::Region, b: &'tcx ty::Region)
+               -> RelateResult<'tcx, &'tcx ty::Region>;
 
     fn binders<T>(&mut self, a: &ty::Binder<T>, b: &ty::Binder<T>)
                   -> RelateResult<'tcx, ty::Binder<T>>
@@ -139,7 +139,7 @@ fn relate_item_substs<'a, 'gcx, 'tcx, R>(relation: &mut R,
 }
 
 pub fn relate_substs<'a, 'gcx, 'tcx, R>(relation: &mut R,
-                                        variances: Option<&ty::ItemVariances>,
+                                        variances: Option<&Vec<ty::Variance>>,
                                         a_subst: &'tcx Substs<'tcx>,
                                         b_subst: &'tcx Substs<'tcx>)
                                         -> RelateResult<'tcx, &'tcx Substs<'tcx>>
@@ -147,19 +147,18 @@ pub fn relate_substs<'a, 'gcx, 'tcx, R>(relation: &mut R,
 {
     let tcx = relation.tcx();
 
-    let types = a_subst.types.iter().enumerate().map(|(i, a_ty)| {
-        let b_ty = &b_subst.types[i];
-        let variance = variances.map_or(ty::Invariant, |v| v.types[i]);
-        relation.relate_with_variance(variance, a_ty, b_ty)
-    }).collect::<Result<_, _>>()?;
-
-    let regions = a_subst.regions.iter().enumerate().map(|(i, a_r)| {
-        let b_r = &b_subst.regions[i];
-        let variance = variances.map_or(ty::Invariant, |v| v.regions[i]);
-        relation.relate_with_variance(variance, a_r, b_r)
-    }).collect::<Result<_, _>>()?;
+    let params = a_subst.params().iter().zip(b_subst.params()).enumerate().map(|(i, (a, b))| {
+        let variance = variances.map_or(ty::Invariant, |v| v[i]);
+        if let (Some(a_ty), Some(b_ty)) = (a.as_type(), b.as_type()) {
+            Ok(Kind::from(relation.relate_with_variance(variance, &a_ty, &b_ty)?))
+        } else if let (Some(a_r), Some(b_r)) = (a.as_region(), b.as_region()) {
+            Ok(Kind::from(relation.relate_with_variance(variance, &a_r, &b_r)?))
+        } else {
+            bug!()
+        }
+    });
 
-    Ok(Substs::new(tcx, types, regions))
+    Substs::maybe_new(tcx, params)
 }
 
 impl<'tcx> Relate<'tcx> for &'tcx ty::BareFnTy<'tcx> {
@@ -473,9 +472,9 @@ pub fn super_relate_tys<'a, 'gcx, 'tcx, R>(relation: &mut R,
 
         (&ty::TyRef(a_r, ref a_mt), &ty::TyRef(b_r, ref b_mt)) =>
         {
-            let r = relation.relate_with_variance(ty::Contravariant, a_r, b_r)?;
+            let r = relation.relate_with_variance(ty::Contravariant, &a_r, &b_r)?;
             let mt = relation.relate(a_mt, b_mt)?;
-            Ok(tcx.mk_ref(tcx.mk_region(r), mt))
+            Ok(tcx.mk_ref(r, mt))
         }
 
         (&ty::TyArray(a_t, sz_a), &ty::TyArray(b_t, sz_b)) =>
@@ -571,11 +570,11 @@ fn relate<'a, 'gcx, R>(relation: &mut R,
     }
 }
 
-impl<'tcx> Relate<'tcx> for ty::Region {
+impl<'tcx> Relate<'tcx> for &'tcx ty::Region {
     fn relate<'a, 'gcx, R>(relation: &mut R,
-                           a: &ty::Region,
-                           b: &ty::Region)
-                           -> RelateResult<'tcx, ty::Region>
+                           a: &&'tcx ty::Region,
+                           b: &&'tcx ty::Region)
+                           -> RelateResult<'tcx, &'tcx ty::Region>
         where R: TypeRelation<'a, 'gcx, 'tcx>, 'gcx: 'a+'tcx, 'tcx: 'a
     {
         relation.regions(*a, *b)