Introduce TyUnusedSubst

Author: bjorn3

src/librustc/ich/impls_ty.rs

@@ -857,7 +857,8 @@ for ty::TypeVariants<'gcx>
             TyChar  |
             TyStr   |
             TyError |
-            TyNever => {
+            TyNever |
+            TyUnusedParam => {
                 // Nothing more to hash.
             }
             TyInt(int_ty) => {

src/librustc/infer/canonical.rs

@@ -634,6 +634,7 @@ impl<'cx, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for Canonicalizer<'cx, 'gcx, 'tcx>
             | ty::TyProjection(..)
             | ty::TyForeign(..)
             | ty::TyParam(..)
+            | ty::TyUnusedParam
             | ty::TyAnon(..) => {
                 if t.flags.intersects(self.needs_canonical_flags) {
                     t.super_fold_with(self)

src/librustc/infer/freshen.rs

@@ -200,6 +200,7 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for TypeFreshener<'a, 'gcx, 'tcx> {
             ty::TyAnon(..) => {
                 t.super_fold_with(self)
             }
+            ty::TyUnusedParam => bug!("Unexpected TyUnusedParam in TypeFreshener"),
         }
     }
 }

src/librustc/traits/coherence.rs

@@ -480,7 +480,8 @@ fn ty_is_local_constructor(ty: Ty, in_crate: InCrate) -> bool {
         ty::TyClosure(..) |
         ty::TyGenerator(..) |
         ty::TyGeneratorWitness(..) |
-        ty::TyAnon(..) => {
+        ty::TyAnon(..) |
+        ty::TyUnusedParam => {
             bug!("ty_is_local invoked on unexpected type: {:?}", ty)
         }
     }

src/librustc/traits/error_reporting.rs

@@ -263,7 +263,8 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                 ty::TyGenerator(..) => Some(18),
                 ty::TyForeign(..) => Some(19),
                 ty::TyGeneratorWitness(..) => Some(20),
-                ty::TyInfer(..) | ty::TyError => None
+                ty::TyInfer(..) | ty::TyError => None,
+                ty::TyUnusedParam => bug!("unexpected TyUnusedParam in fuzzy_match_tys"),
             }
         }
 

src/librustc/traits/query/dropck_outlives.rs

@@ -261,5 +261,7 @@ fn trivial_dropck_outlives<'cx, 'tcx>(tcx: TyCtxt<'cx, '_, 'tcx>, ty: Ty<'tcx>)
         | ty::TyAnon(..)
         | ty::TyInfer(_)
         | ty::TyGenerator(..) => false,
+
+        ty::TyUnusedParam => bug!("trivial_dropck_outlives called with TyUnusedParam"),
     }
 }

src/librustc/traits/select.rs

@@ -2039,7 +2039,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 ))
             }
 
-            ty::TyProjection(_) | ty::TyParam(_) | ty::TyAnon(..) => None,
+            ty::TyProjection(_) | ty::TyParam(_) | ty::TyUnusedParam | ty::TyAnon(..) => None,
             ty::TyInfer(ty::TyVar(_)) => Ambiguous,
 
             ty::TyInfer(ty::CanonicalTy(_)) |
@@ -2120,6 +2120,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 bug!("asked to assemble builtin bounds of unexpected type: {:?}",
                      self_ty);
             }
+            ty::TyUnusedParam => bug!("Unexpected TyUnusedParam in copy_clone_conditions"),
         }
     }
 
@@ -2155,6 +2156,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             ty::TyParam(..) |
             ty::TyForeign(..) |
             ty::TyProjection(..) |
+            ty::TyUnusedParam |
             ty::TyInfer(ty::CanonicalTy(_)) |
             ty::TyInfer(ty::TyVar(_)) |
             ty::TyInfer(ty::FreshTy(_)) |

src/librustc/ty/context.rs

@@ -1947,13 +1947,15 @@ macro_rules! sty_debug_print {
                     region_infer: 0, ty_infer: 0, both_infer: 0,
                 };
                 $(let mut $variant = total;)*
+                let mut TyUnusedParam = total;
 
 
                 for &Interned(t) in tcx.interners.type_.borrow().iter() {
                     let variant = match t.sty {
                         ty::TyBool | ty::TyChar | ty::TyInt(..) | ty::TyUint(..) |
                             ty::TyFloat(..) | ty::TyStr | ty::TyNever => continue,
                         ty::TyError => /* unimportant */ continue,
+                        ty::TyUnusedParam => &mut TyUnusedParam,
                         $(ty::$variant(..) => &mut $variant,)*
                     };
                     let region = t.flags.intersects(ty::TypeFlags::HAS_RE_INFER);

src/librustc/ty/error.rs

@@ -232,6 +232,7 @@ impl<'a, 'gcx, 'lcx, 'tcx> ty::TyS<'tcx> {
                     "type parameter".to_string()
                 }
             }
+            ty::TyUnusedParam => "unused type parameter".to_string(),
             ty::TyAnon(..) => "anonymized type".to_string(),
             ty::TyError => "type error".to_string(),
         }

src/librustc/ty/fast_reject.rs

@@ -121,7 +121,7 @@ pub fn simplify_type<'a, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
         ty::TyForeign(def_id) => {
             Some(ForeignSimplifiedType(def_id))
         }
-        ty::TyInfer(_) | ty::TyError => None,
+        ty::TyInfer(_) | ty::TyError | ty::TyUnusedParam => None,
     }
 }